Rosie gave Hope the Tiger Miraculous to defend herself...and ended up having to use Clout,the Tiger Miraculous's ability. It scales in power with the emotions of the user,and since she had to use Clout on her parents to put them out of their misery just before him,this Clout ended up vaporizing this poor fellow.

Hope had considered giving up her identity as Weretigress,but her parents wouldn't want her to,so she hasn't.