Necromancy gave us two tactical area denial spells: miasma and cloud of ashes. They are quite good, but their tactical possibilities are limited since you need to still cast them on a player. No player in a place you want to cast that cloud, no cloud. Now AoE spells like auw surge are ok, if you could cast them in a general direction they'd be OP in small scale, you wouldn't even need to aim to cast them and hit an enemy, but i don't think it would be OP with miasma and cloud of ashes. It's really weird that you can't cast area denial spells where you want them.