Malachai's Simula and Blood magic question

so im a blood mage by spec

but if i use this does it only apply to the gems inside? or to all of me? larger question could i refund the blood magic skill if i watnted to?

It applies to every skill you use.

The item grants the Blood Magic ability as if you had taken the passive. It doesn't actually give you the keystone. That means there is nothing to refund. If you don't want to spend your Life instead of Mana anymore, simply unequip the item.

Items like this that grant Keystone abilities are great ways to use the ability without actually investing points in the passive tree to acquire the Keystone.

Edit: I see you you have the Blood Magic Keystone in the passive tree. Yes, you can respec out of it.

thats what i figured.

I was saying that because i already spec into blood magic i was thinking about refunding it and using this cuz i am stacking lightning damage so this would be ideal for me minus the crap defenses

The only thing you have to keep in mind is the 100% Mana cost of skills on Malachai's. It might be convenient to get Blood Magic and it might boost your Lightning Damage, but all your skills will cost twice as much health.