That's a good point, but Tini never actually explained what were these costs. She also never explained Teddy's comment implying Billy's powers are from a different dimension (?) or something like that. And on Strikeforce, she never brought up any of the stuff from Death's Head as an explanation for what was happening with Billy's powers; she just said he was tired. I guess we'll have to see what kind of stories Billy will have in Strikeforce, because right now I'm not convinced there is an actual story behind what's happening with his powers.