Use Event Horizon to ensure Dark Matter hits your target.
Veigar has very low health, so it is advisable to select at least one defensive summoner spell.
Move away from Yone’s (E)-(Q) when he has two stacks of (Q). Yone can ignore the stun on Veigar’s [E] when he retreats with (E), so use [E] to stop him from closing in instead.