There are no mobs that can "kill you before you can move" (implying on turn 1) in any Wizardry, not in any level-appropriate area.
Wiz6 final dungeon, you run into a mob of priests of Ramm who start spamming death wish and lifesteal. You are dead.
You run into 5 chunins who start instakilling your dudes with kirijutsu because they move first with their turbo speed. You are dead.
Isle of the dead, you run into some banshees who start spamming death and lifesteal. You are dead.
Wiz7, you run into a mob of T'rang assassins who paralyze, kill and veggify all your dudes before they can act. You are dead.
Lifesteal is a single target spell bro and it in no way can kill "any monster in the game".
Lifesteal's damage scales exponentially and differently from other spells, to the point that it can indeed kill any monster in the game and hit something for 1k damage.
I missed the 'aoe' part tho on dat freezing sphere, I thought he only meant the 1000 damage that was dumb