User blog comment:Toshiroichigo/Kensei and Rose's Deaths- Were they Necessary?/@comment-5398287-20140430220623

"They were vizards and captain level shinigamis. How could they be wiped out in one blow?"

Gremmy imagined them dead, and they were dead. It's as simple as that. No amount of physical or spiritual power can stop imagination. If they had been killed with a single physical attack, I would wholeheartedly agree with you, but their power and racial status had no way of preventing how they died, unfortunately.