Cassiopeia vs LeBlanc Matchup Guide

Cassiopeia

Cassiopeia

Mid Lane Control Mage

The Serpent's Embrace – sustained DPS battlemage without boots

VS
LeBlanc

LeBlanc

Mid Lane Assassin

High-mobility burst mage with chain root and mimicked recast

VerdictSkill matchup EarlyOpponent Favored MidSkill Matchup LateCassiopeia Favored Updated Sep 15, 2025 · Patch 25.18

Champ Select Cheat Sheet — Cassiopeia vs LeBlanc

Runes
Conqueror, Presence of Mind, Legend: Haste, Last Stand
Secondary: Manaflow Band, Transcendence
Summoners
Flash + Teleport
Start
Doran's Ring (400g) + 2 Health Potions (100g) or Corrupting Potion (500g) vs poke
Core Build
TearArchangel's StaffRylai's Crystal ScepterLiandry's Torment
Trade Pattern
Pre-6: Q max range > 2x E > out; Post-6: Q > 3x E > step back
Short trades until Archangel's; never E without poison.
Danger Levels
Respect LeBlanc at levels 3, 6
First Back
Tear of the Goddess (400g)
Ideal Back (900–1150g)

Matchup Dynamics

How This Matchup Works

Cassiopeia vs LeBlanc pivots at level 3 when W grounds dashes and at first item (Archangel's/Rylai's). LeBlanc threatens early windows; Cass wins sustained DPS after 2 items.

Early Game (1-5)

Opponent Favored - Assassin windows dominate pre-6; only trade after Q tag and with W down; keep wave close to tower.

Mid Game (6-11)

Skill Matchup - Even—assassin still lethal, but W+Archangel's shield lets Cass contest waves and punish over-extends.

Late Game (12+)

Cassiopeia Favored - Cass sustained DPS wins extended fights; set W zones in chokes and front-to-back.

Key Interactions

  • W – MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities. vs E dashes: Drop W – MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities. under LeBlanc when E starts; ground prevents dashes/blinks for 5s; punish with Q – Noxious BlastQ – Noxious BlastCassiopeia blasts an area with Poison after a brief delay, granting her increased Move Speed if she hits an enemy champion. > E – Twin FangE – Twin FangCassiopeia lets loose an attack that deals increased damage to Poisoned targets and heals her for a percentage of the damage dealt. If the target dies from this attack, Cassiopeia regains Mana. while grounded (0.75s E CD on poison).
  • Bait key cooldown: W – DistortionW – DistortionLeBlanc dashes to a location, dealing damage to enemies near her destination. For the next 4 seconds, activate Distortion again to return LeBlanc to her starting location. / mobility: Wait out W – DistortionW – DistortionLeBlanc dashes to a location, dealing damage to enemies near her destination. For the next 4 seconds, activate Distortion again to return LeBlanc to her starting location. then step with GhostGhostGain Move Speed and ignore unit collision for the duration. after it ends (~14–18s CD early); trade Q – Noxious BlastQ – Noxious BlastCassiopeia blasts an area with Poison after a brief delay, granting her increased Move Speed if she hits an enemy champion. > E – Twin FangE – Twin FangCassiopeia lets loose an attack that deals increased damage to Poisoned targets and heals her for a percentage of the damage dealt. If the target dies from this attack, Cassiopeia regains Mana. until they exit kill range.
  • Face for stun: Turn to face just before commit so R – Petrifying GazeR – Petrifying GazeCassiopeia releases a swirl of magical energy from her eyes, stunning any enemies in front of her that are facing her and slowing any others with their back turned. stuns; follow with E – Twin FangE – Twin FangCassiopeia lets loose an attack that deals increased damage to Poisoned targets and heals her for a percentage of the damage dealt. If the target dies from this attack, Cassiopeia regains Mana. chain resets.
  • Shadow/clone denial: Cast W – MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities. on W or shadow/clone position to block re-engage; hold R – Petrifying GazeR – Petrifying GazeCassiopeia releases a swirl of magical energy from her eyes, stunning any enemies in front of her that are facing her and slowing any others with their back turned. until after gap-closer is forced (3–5s window).

Cassiopeia

Strengths

  • Sustained DPS: E resets at 0.75s on poisoned targets allow 3–4 casts/s mid game
  • Anti-dash control: W grounds and slows, blocking most gap-closers
  • Zone control: Q + W forces awkward farm angles; punish cannon timings

Weaknesses

  • No dash; gankable pre-6 if wave pushed
  • Mana-gated until Tear/Archangel’s; missed Q reduces trade power
  • R needs facing for stun; mistime yields only slow

LeBlanc

Strengths

  • Explosive all-ins with R – MimicR – MimicLeBlanc casts a mimicked version of one of her basic spells. once level 6
  • Multiple dashes or bursts (E – Ethereal ChainsE – Ethereal ChainsLeBlanc launches a chain that shackles the first enemy hit. If the target remains shackled for 1.5 seconds, LeBlanc roots them and deals additional damage.) to dodge Q and exit
  • Snowballs off early kills; dive with jungler at ~3:30

Weaknesses

  • Grounded by W; cannot dash/flashFlashTeleports you a short distance toward your cursor. inside zone
  • Falls off into Cass sustained DPS with Rylai’s + Liandry’s
  • Telegraphed engage windows allow counter-ult stuns

Power Curve Comparison EXPERIMENTAL

Power Curve Visualization

Win Conditions

Cassiopeia's Win Condition

  • Freeze 6–8 minions from tower pre-6; call jungler at 3:15 for grounded W gank
  • Crash Wave 4 for Tear buy; TP back if needed to keep prio
  • Front-to-back at objectives with W zones; face before R to stun carry

LeBlanc's Win Condition

  • Trade on Cass Q miss; force pre-6 all-ins with jungler
  • Roam on shoved waves before Cass gets Archangel's
  • Avoid extended fights inside MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities.; play to sides and flanks

Laning Phase Guide

Level/Phase Cassiopeia LeBlanc
Level 1 Start Q – Noxious BlastQ – Noxious BlastCassiopeia blasts an area with Poison after a brief delay, granting her increased Move Speed if she hits an enemy champion.; last-hit; tag on cs; keep wave even; ward raptor brush at 2:20 if pushing; no all-in pre-2. Start Q; poke on last-hits; avoid walking into Q radius; ward pixel at 2:20 if pushing.
Level 2 Take E – Twin FangE – Twin FangCassiopeia lets loose an attack that deals increased damage to Poisoned targets and heals her for a percentage of the damage dealt. If the target dies from this attack, Cassiopeia regains Mana.; punish only after Q hits; 2x E then out; crash at ~2:40 if HP lead to buy Tear. Take W; trade when Cass Q misses (3.5–4.5s); thin wave to avoid freeze.
Level 3 Take W – MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities.; place on minions to deny dash paths; call jungler at 3:15 for grounded setup; all-in only if Q hits. Respect E – Ethereal ChainsE – Ethereal ChainsLeBlanc launches a chain that shackles the first enemy hit. If the target remains shackled for 1.5 seconds, LeBlanc roots them and deals additional damage. or Q – Sigil of MaliceQ – Sigil of MaliceLeBlanc projects a sigil, dealing damage and marking the target for 3.5 seconds. Damaging the marked target with an ability detonates the sigil, dealing additional damage.; do not dash inside MiasmaW – MiasmaCassiopeia releases several clouds of poison, slowing, grounding, and lightly damaging enemies that pass through them. Grounded enemies cannot use Movement abilities.; keep lane centered before 3:30 gank.
Level 4-5 Hold freeze 3–4 waves; punish cannon with Q>E; ward opposite river at 4:00; recall on Wave 4 (first cannon) for Tear + Dark SealDark SealProvides Ability Power and Mana. Increases in power as you kill enemies.. Shove with waveclear; hover to one side with ward; prevent freeze by last-hitting casters late.
Level 6 Track jungle; turn ganks with R by facing; pre-place W; if R stuns, E-chain to kill; don’t R if they’re not facing. Look for R window when Cass Q is down; bait R by turning away; break vision to reduce stun odds.
Level 7-8 Stack Tear; seek trades after Q; force objectives with shove; TP at 10:00 Unleashed TP timing. Roam only after pushing; avoid fighting in river choke vs W zone; track Cass GhostGhostGain Move Speed and ignore unit collision for the duration./TP.
Level 9 E max online; take 2–3 wave trades; set up vision at 9:30 for herald; swap to sweeper if ahead. Respect perma-slow if Cass has Rylai’s; buy Null-Magic/Seeker’s as needed; farm under tower.

Power Spikes

Level Spikes

Cassiopeia LeBlanc
Level Description Level Description
2 Minor Q + E loop online; trade only after Q hits. 3 Major Full combo access; kill pressure with gap closers.
3 Major W grounds dashes; set up ganks and deny engage. 6 Critical Ultimate unlocks lethal all-ins.
6 Critical R turn potential; face to stun on all-in. 11 Minor Rank 2 ultimate increases execute/burst.
9 Major Maxed E reaches 0.75s CD on poison; DPS spike.

Item Spikes

Cassiopeia LeBlanc
Item Description Item Description
Tear of the GoddessTear of the GoddessIncreases maximum Mana as Mana is spent (400g) Fix mana; start stacking early. First legendary (Luden's/Stormsurge/Seraph/QSS/etc.) (2600–3000g) Damage or safety spike depending on choice.
Archangel's StaffArchangel's StaffIncreases Ability Power based on maximum Mana (2900g) Mana → AP + shield; unlock spam trades. Serrated DirkSerrated DirkIncreases Attack Damage and Lethality spike (1100g) Assassins gain one-shot thresholds pre-6.
Rylai's Crystal ScepterRylai's Crystal ScepterAbilities slow enemies (2600g) Perma-slow keeps targets inside Q/W for E chains. Zhonya's/Maw/Banshee's (2800–3100g) Defensive buy shifts skirmishes.
Liandry's TormentLiandry's TormentCharge up in combat to deal high damage over time, especially against durable enemies (3000g) Burn shreds tanks; synergizes with Rylai’s.
Zhonya's HourglassZhonya's HourglassActivate to become invincible but unable to take actions (3000g) Stasis vs assassin ults; bait then re-engage with R.

Best Build for Cassiopeia

Starting Items

Doran's RingDoran's RingGood starting item for casters (400g) + 2 Health Potions (100g) or Corrupting PotionCorrupting PotionRestores Health and Mana over time and boosts combat power - Refills at Shop (500g) vs poke

Core Items

Tear → Archangel's StaffArchangel's StaffIncreases Ability Power based on maximum Mana → Rylai's Crystal ScepterRylai's Crystal ScepterAbilities slow enemies → Liandry's TormentLiandry's TormentCharge up in combat to deal high damage over time, especially against durable enemies

Runes

Primary: ConquerorConquerorGain stacks of adaptive force when attacking enemy champions. After reaching 12 stacks, heal for a portion of damage you deal to champions., Presence of MindPresence of MindRestore a small amount of mana or energy when damaging an enemy champion. Takedowns restore mana or energy., Legend: HasteLegend: HasteTakedowns on enemies grant permanent Basic Ability Haste., Last StandLast StandDeal more damage to champions while you are low on health.

Secondary: Manaflow BandManaflow BandHitting an enemy champion with an ability permanently increases your maximum mana by 25, up to 250 mana.After reaching 250 bonus mana, restore 1% of your missing mana every 5 seconds., TranscendenceTranscendenceGain bonuses upon reaching the following levels:Level 5: +5 Ability Haste Level 8: +5 Ability Haste Level 11: On Champion takedown, reduce the remaining cooldown of basic abilities by 20%.

Summoner Spells

FlashFlashTeleports you a short distance toward your cursor. + TeleportTeleportAfter a brief channel, become untargetable and travel to an allied unit. Upgrades into Unleashed Teleport, which significantly increases travel speed.

Priority Build Path

1
Archangel's Staff

Mana to AP + shield lets you frontload E spam.

2
Rylai's Crystal Scepter

Perma-slow to stick/kite on W.

3
Liandry's Torment

Burn amplifies DPS in extended fights.

4
Zhonya's Hourglass

Stasis vs dive; core vs assassins.

Situational Adjustments

  • Banshee's VeilBanshee's VeilPeriodically blocks enemy abilities: Versus pick/long-range engage (e.g., Ahri E, Syndra E)
  • MorellonomiconMorellonomiconIncreases magic damage: Versus heavy healing (Sylas/Aurelion Sol)
  • Rabadon's DeathcapRabadon's DeathcapMassively increases Ability Power: When ahead needing raw DPS 3rd/4th

Key Patterns

Lethal Combos

Cassiopeia Full Combo (Level 6+):

Q – Noxious Blast hit > W – Miasma under target > spam E – Twin Fang 4–6 times > R – Petrifying Gaze when they face > E – Twin Fang to finish

Lethal at ~30–40% HP with Liandry’s + Rylai’s.
LeBlanc Escape/Counter Combo:

Sidestep Q; wait out W – Miasma; commit with R – Mimic then exit before Cass R – Petrifying Gaze

Burst before Archangel’s shield procs.

Trading Combos

Cassiopeia Short Trade:

Pre-6: Q max range > 2x E > out; Post-6: Q > 3x E > step back

Short trades until Archangel's; never E without poison.
LeBlanc Quick Trade:

Trade after Cass Q misses; 1–2 autos/abilities then disengage

Punish mana use; avoid fighting inside W.

Lethal Thresholds

  • Cassiopeia Kill Range: R stun + 4–6 Es with Liandry’s burns 1200–1600 HP; ~30% HP kill if poisoned.
  • LeBlanc Kill Range: Assassins: 100–0 at 6 with IgniteIgniteDeals true damage over time to target enemy champion and reduces healing effects on them for the duration. when Cass <900 HP; mages: burst <40% HP if R lands.
  • Critical Levels: Cass 3/6/9; Opp 3/6/11

Level by Level Game Plan

Level Primary Goal Lane Position Trading Opportunities Kill Windows Setup Opportunities
1 Farm safely; tag with Q if free Midline or slight pull Only after Q hits Low Stack for level 2 first
2 Unlock E trades Keep wave 6–8 from tower Q>2xE then out Low HP >60%
3 Control with W Freeze near tower Ground then Q>E Medium vs dash champs Ping jungler 3:15–3:45
4-5 Cannon recall Crash Wave 4 then base Short Q>E pokes Low Buy Tear + Dark SealDark SealProvides Ability Power and Mana. Increases in power as you kill enemies.
6 R turn Hover safe side Hold R as counter High if R stuns Place W before commit
7-8 Tempo with TP Push then move Extended with items Medium Deep wardDeep WardYour wards in the enemy jungle are Deep, gaining Health and Duration.Level 9: Wards in the river are also Deep. path
9+ Transition to mid Control prio E spam on poison High with Rylai’s Vision for objectives
Mid Game (11-16) Skirmish wins River/jungle control Front-to-back on W Pick into W zone Start objectives after shove
Late Game (16+) Teamfight execution Backline anchor Kite on W zones Chain E on stun Keep FlashFlashTeleports you a short distance toward your cursor. for self-peel

First Back Goals

Ideal Back (900–1150g)

  • Tear of the GoddessTear of the GoddessIncreases maximum Mana as Mana is spent (400g)
  • Dark SealDark SealProvides Ability Power and Mana. Increases in power as you kill enemies. (350g)
  • Amplifying Tome (400g)

Crash Wave 4 (first cannon) ~2:30–3:00; recall; TP back if needed.

Standard Back (700–900g)

  • Tear of the GoddessTear of the GoddessIncreases maximum Mana as Mana is spent (400g)
  • Refillable Potion (150g)
  • Control Ward (75g)

Recall after pushing on cannon; avoid non-cannon recall.

Teamfight Tips

Aspect Cassiopeia LeBlanc
Primary Role Backline DPS/control mage Assassin/burst/control depending on champ
Target Priority Closest diver
Enemy carry inside W
Frontline <40% HP		 Eliminate Cass first or isolate backline
Objective Control Set W in chokes for drake/baron
Hold R for turn on facecheck		 Engage before Cass sets zones
Flank to force her R slow
Positioning Front-to-back in chokes (river/jungle entrances)
Avoid wide spaces where enemies spread		 Flank or long poke to force early R
Other Tips Face the biggest threat before R to guarantee stun
Layer W on carries to block FlashFlashTeleports you a short distance toward your cursor.; chase with GhostGhostGain Move Speed and ignore unit collision for the duration.		 Bait R by turning away; fight out of W zones