They weren't blasted off their just really badly broken to the point she can't move them. Which Grimm will fix afterwards. Because, he hates seeing his allies harmed. Right now Krystaal is an enemy. I should have been more specific, but her hands were [u]not[/u] blasted off.

Edit: Also unlike a lot of people Grimm isn't resistant to being electrocuted. He's got huge bleeding gashes in his calves from Krystaals claws, and a lot of juice still pumping through his body. Oh, and you're forgetting the other crucial thing, he's been eating souls the entire time before coming to the hangar. Their wasn't a shortage of them thanks to everyone going on their killing sprees. So I'd say Grimm is appropriately strong, for what's been going. So if he so chose he could have made Krystaal completely explode, then resurrect her later when she wasn't such a pain in the bum.

Edit 2: I also hardly to never have Grimm on the front line fighting. Also the only one stronger then him would by Abyss. So he's not OP!

Edit 3: I'm editing my whole post just to make you all happy.