Please note that this stream may contain spoilers for Kingdom Hearts III.
I think the power of waking might be some sort of resurrection through accessing some ones passing heart. This is because at the end of kh3 Mickey tells Sora he can't just use the power of waking how ever he wants there would be consequences for using it in such a way when he went to go get Kairi who was obviously dead. The consequence being his own life and this is why he disappears at the end. But idk so don't take my word just my thoughts