Grimrock

So far I am a fair bit in the game and encountered a swirling twister of leaves which follows me. I cannot kill it, every time I attack it I get 0 hits, nothing I use will harm it. Any help appreciated

These are Air Elementals. They show up once you passed certain points of the game world and you can have at least one method of dealing with them. This post i made earlier should help you out.

I wouldn't waste a point in water magic just to get Dispel, nor a Gold key for the Acolyte Staff (unless you want it for other reasons). imo, the best way is to get the Ethereal Dagger from the cemetery and pass it from character to character so each can take a swing.