Sion

Crystallize (W) wall blocks the Unstoppable Onslaught (R) charge path entirely. Glacial Storm (R) chilled plus Frostbite (E) shreds the Soul Furnace (W) shielded HP before he can resolve the Decimating Smash (Q) channel.

Precision Protocol (Q2) true damage and Sundered Sky burst chunk huge HP pools. The Hextech Ultimatum (R) prevents Unstoppable Onslaught (R) repositioning back to team, and Hookshot (E) cancels Decimating Smash (Q) charge.

Riposte (W) parries Decimating Smash (Q) on the charge windup and stuns Sion back. Grand Challenge (R) Vital procs deal percent-HP true damage that scales on max HP — exactly what Sion stacks — and Lunge (Q) plus Bladework (E) keep her sticking outside Q range.

Boomerang Throw (Q) pokes Sion out of CS from outside Decimating Smash (Q) range, and Hop (E) plus Hyper (W) move-speed kite the slow Q windup. Mega Gnar GNAR! (R) knock-up cancels Sion's Q charge cleanly when he closes the gap.

Decimating Smash (Q) windup telegraphs his commit; Soul Furnace (W) shield is broken before the engage reaches Heimer. CH-2 Electron Storm Grenade (E) stun interrupts the Q charge, and Unstoppable Onslaught (R) is steered into turrets via Heimer repositioning.

Decimating Smash (Q) has a long windup that Counter Strike comfortably covers, and Roar of the Slayer (E) does not interrupt the dodge stance. Once the AOE stun lands on the recast, Sion has no dash to leave and Jax stacks Relentless Assault for free.

Soul Furnace (W) HP stacking is Sion's core strength — Bio-Arcane Barrage (W) deals % max HP magic damage on every auto, melting his stacked HP faster than the shield refunds.

Soul Furnace (W) HP stacking gets shredded by Liandry's Torment plus Dream-Laden Bough (P) passive max-HP burn — Sion's massive HP pool melts faster than the shield refunds.

Ragnarok cleanses Sion's Decimating Smash channeled knock-up at the moment of impact, denying him the lock his Soul Furnace tank engage needs. Roar of the Slayer slow is ignored under R immunity,

Sion telegraphs his Decimating Smash channel from a long windup, giving Orianna time to park the Ball on his team's stacking spot. Command: Shockwave pulls all his teammates clumped behind Sion's engage,

Super Scorcher Breath (Q) 225-stack evolution deals true damage based on max HP, and Sion's Glory in Death passive HP pool plus Soul Furnace (W) stack make him a bigger trophy. Decimating Smash (Q) is a 2-second charge that Achooo! (W) interrupts before the stun lands.

Subjugate (R) drains Sion's stacked HP and resists exactly during the Glory in Death (R) revive window, and Chomp (Q) auto-reset deals percent-HP damage. Pillar of Ice (E) blocks the Decimating Smash (Q) walk-up path and cancels Unstoppable Onslaught (R) trajectory.

Sion's Glory in Death passive resurrects him into a high-HP run-down state for 10 seconds. Contaminate E per-stack execute plus Lord Dominik's Regards turn his bar into a free target, Spray and Pray R chains across his Unstoppable Onslaught R charge,

Urgot W Purge channel out-DPSes Decimating Smash (Q) wind-up because Sion has to charge for ~2 seconds while Purge ticks every 0.25s. E Disdain knock-up cancels Unstoppable Onslaught (R) charge mid-roll, and Q Corrosive Charge slow keeps him inside the Purge cone.

Silver Bolts (W) third-hit max-HP true damage scales with Sion's massive HP pool from Soul Furnace (W) shield stacks, melting through his armor. Tumble (Q) repositions out of Decimating Smash (Q) and Condemn (E) stuns him into the wall during Unstoppable Onslaught (R) charge.

Sion telegraphs stacking on his Unstoppable Onslaught (R) charge, so Viktor steers Arcane Storm (R) onto the cluster for ten seconds of AOE damage. Gravity Field (W) stuns him during Decimating Smash (Q) wind-up and Hextech Ray (E) chunks through Soul Furnace (W) shield stacks.