[Sailor Chaos]

In the manga its basically implied that Mamoru died and this is just an evil spirit in his body. With his soul being gone until Usagi saves him.

Edit: Sorry didn't see PRX already said this.

But while I am editing.... I.really liked the episode. Endo was chiling and Usagi was really pushed to the emotional limit here. Crazy how they ended up in the Command Center. Beryl showing up made for a good cliffhanger.