Eureka

Pairs with passive for massive AP and ability haste.

Ethereal Weapon procs Lux's passive — E into multiple enemies and you can detonate the passive mark on all of them.

Pure AP is squishy and damage-light — go half-tank and stack CDR for faster passive procs. Use R to clear waves.

Play this when the enemy lineup is squishy. RQ for explosive damage.

R deals % magic damage — level 3 base is 30%, +16% at 800 AP, and 3500 AP hits 100% max HP.

Void Rift is magic damage, so it fits AP champions with high magic pen — % magic pen amplifies it, and Pridestalker's ability damage procs it many times. Forge: magic pen > AP > MS.

At 500 ability haste, R has only a 12s cooldown.

Syndra's QE triggers Slap Around twice; hitting multiple enemies stacks it extra fast.

Mystic Punch's CDR + Dusk and Dawn enables infinite Q.

Classic Fizz — one-shot low-HP enemies, then Zhonya's or Fey Magic E to bail. Fey Magic is the key tech; haste is your top priority for high uptime.

Ziggs's CDs are already short — stack haste and play it like URF.

Very ability-reliant — prioritize stacking ability haste.

100+ haste + Archmage = infinite Q.

Stack CDR and plant shrooms everywhere.

Once CDR is high, infinite E permanently jails enemies.

After casting R, press R again to control the bear — Killing Time still triggers. Stack CDR for seamless bear chains and Killing Time uptime; stored damage explodes as true damage, huge amp.

Combine Archmage with ~300 ability haste for infinite R.

Mystic Punch infinite knockup build.

Use Q for huge damage. Standard AP build, no heavy hex reliance; with Cruelty, build Stormsurge first.

Use hexes to slash R's CD. Take any R-CDR hex; Ultimate Revolution is even better.

AP burst. Standard build, any of the listed runes work.

Use W's CC and damage to torture enemies. Once W-CDR + Eureka spawn, it's good to go.

High damage, good tolerance, long R cooldown.

AP Irelia — damage from EWR.

Infinite raining bullets.

Ascended Ryze. Operation + luck = win.

Eureka is another excellent Karthus spike, giving him frequent ult pressure and strong snowball tempo.

Damage is huge but fragile.

AP build amps Twitch's passive true damage and E burst; W's huge slow locks enemies down. Slows don't stack — no Rylai's. Twitch's passive can't proc Liandry's or Ethereal Weapon — don't pick those.

After picking Eureka, step back after casting E so Eureka triggers — otherwise it doesn't proc.