Sion vs Cassiopeia — Top Lane Matchup Guide

How to win lane as Sion against Cassiopeia · 53.72% win rate over 1,262 Emerald+ games · Updated 2026-07-27

Verdict: Winnable despite the lane — Cassiopeia owns 6 of the 7 game windows, yet the win rate favours Sion: survive their windows and the game is yours. Sion wins 53.72% of games vs Cassiopeia in top lane (1,262 Emerald+ games analysed).

Favour timeline — who owns each window

StageFavouredWhy
Level 1Even / skillNeither champion has their full kit — Cassiopeia lacks Miasma at level 1, so brush-angled Q charges are briefly possible, but she can still poke through Twin Fang spam without committing to melee range.
Level 2CassiopeiaMiasma (W) comes online at level 2 and immediately grounds your R engage; every step forward is punished by a poison zone that cancels your unstoppable charge before it reaches her.
Level 3CassiopeiaHer full three-spell combo (Q poison cloud, W Miasma zone, E Twin Fang) is now active; she pokes you through the wave and the grounding effect means your W-shield is your only real trading tool.
Levels 4-5CassiopeiaLevels 4-5 are a pure kite war — Cassiopeia has no need to step in range, and your Q charge is telegraphed enough that she simply repositions; farm under your tower and do not chase.
Level 6CassiopeiaYour R engage at level 6 runs directly into her R face-stun — she turns and instant-stuns you mid-charge, then shreds the stunned target; use Unstoppable Onslaught to roam, not to all-in Cassiopeia.
First itemCassiopeiaHeartsteel spikes your HP total but Cassiopeia's Twin Fang damage scales with her AP items simultaneously; the first-item duel still favours her sustained DPS and she can kite Heartsteel's proc range indefinitely.
Two+ itemsCassiopeiaFull-AP Cassiopeia's Twin Fang melts your HP pool in seconds at 2+ items and her Miasma denies any melee retaliation; never solo-duel her — force teamfights where your zombie passive and HP bulk zone her team.

Early game (levels 1–5)

You cannot charge Q openly against Cassiopeia at level 1 — she has no Miasma yet, but her Twin Fang (E) poke punishes slow channels hard. Use the brush at the side of the lane or the wave itself as cover; if she steps up to last-hit a pushed wave she briefly leaves poke range and that is your only free charge window. W-shield absorbs one or two Twin Fang hits without meaningful HP loss, so do not panic-detonate it — hold it until you are ready to walk forward and she cannot poison through it fast enough to break even. Doran's Shield and a Magic Resist shard are mandatory; take Mercs if you expect Miasma to dominate the mid game.

Read the rest of this matchup

The full Sion vs Cassiopeia report continues with the mid-game plan, the late-game and teamfight plan, every power spike to play around, and the win conditions for both sides — plus cooldown tracking and the live enemy-jungle tracker inside the app.

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