Power is dead, it could only be the blood demon. Though I would make more sense for she to be conquest... I think It could also be death. If you think about how Denji has this whole dialog about never being ready for death, It would make sense for here to be traumatized (expiriencing death many times) or something like thatdid some one else also tought that the girl show in the last panel would be power?
She could be the new Control Devil thou. Breaking respawn time records of courseOh Death is here, we're so fucked, there's no happy ending in sight.