If you attempt to spawn a blaze, using an angry doll, in a room that's too small (such as 5x5x3) then the blaze can sometimes fail to spawn, but the doll and lava still get used up. Could you either make several attempts to spawn, or not consume the materials if the spawn fails?

Dangit, this is an Ex Nihilo issue, not Ex Astris. Do you want me to close this and open one in the ex nihilo repository?

Done

Would probably be a good idea, otherwise I'll forget.