Alright. There's no point in reviving Watanuki if you aren't in a solid state as well.
Keep in mind though... he's not empty. I know what it looks like now, but this isn't quite Ter, it's not an overwrite. There were only two rooms in his heart that weren't destroyed: an archival room with his relationships, and Ter's room. Think of it like... those two remaining people in the whole heart are all that's there, so that's what we see.