Nasus is a dashless melee, so even when he tries to farm with Siphoning Strike (Q) he keeps getting pushed off the lane by the longer-range Baleful Strike (Q), and once trapped by Event Horizon (E) he has no escape and eats the full Primordial Burst (R).

Annie has no mobility, so she is constantly poked by the longer-range Baleful Strike (Q), and if she steps up she gets locked by Event Horizon (E) and punished with the stun-into-Primordial Burst (R) combo.

Until Unstoppable Force (R), Malphite is a dashless melee who takes constant Baleful Strike (Q) poke, and when he closes in he is easily caught by Event Horizon (E) and hit by Primordial Burst (R).

Veigar has no mobility, so after level 5 Kassadin uses Riftwalk (R) to jump over Event Horizon (E) and dive in, cuts Veigar's combo with Null Sphere (Q)'s silence, and overwhelms him in the late game.

Zed uses Living Shadow (W) to teleport out of Event Horizon (E) and bursts Veigar first with the Death Mark (R) combo.

Fizz uses Playful / Trickster (E) to become untargetable, shrugging off Event Horizon (E)'s stun and Primordial Burst (R) before all-inning.

Katarina uses Shunpo (E) to leap over and dodge Event Horizon (E), and with Voracity (P) resetting her cooldowns on a kill she explosively bursts Veigar down.

Akali uses Twilight Shroud (W) stealth and the dashes of Shuriken Flip (E) and Perfect Execution (R) to dodge Event Horizon (E)'s stun, close in, and pick Veigar off.