This is a spawnpoint I can get excited about
Very cool. I'd already said in a couple of other threads that I figured the Necro would be able to make use of the Sacrificial Altar and this is just one of several ways I'm sure he will be able to do so.
The wording on this card is...very strange. If the intent is just that you can only gain mana once per turn, why not just say: "Once per round, after a creature is destroyed, gain mana equal to its level"? Wouldn't that be clean and unambiguous? But the current wording is muddy and makes it sound like you can gain mana from each creature that dies, but only upon its first death in the round. If the intent is the former, then the wording is very poorly done.