Veigar Summoner Spells

ive always taken the traditional AP mid route flash ignite, but i find myself with extreme excess damage or ignite just isn't enough.

looking at the alternatives i could pick up ghost/heal/barrier to keep myself alive, but my thinking has always been dont get caught out and you wont even need those.

so i was thinking to replace ignite with cleanse/clarity/clairvoyance/teleport as an alternative. but each of those seem really niche as well.

so exhaust to help more with the 1v1?