Masou Gakuen HxH Season 1 Episode 11

Operation Take Back Tokyo -Apocalypse-

The attack on Tokyo has begun, and Amaterasu finds itself outgunned by the Batlantis royal guards. It's up to the newly powered-up Sylvia to save her the day with her Hybrid Heart. When the defeated enemy general uses her ultimate attack to summon a black hole that can take out Tokyo, she'll have to rely on her forbidden weapon to save the city.