Why Manaphy's ability is still working even it is knocked out?？

Riko0919

I am using Radiant Greninja's Moonlight Shuriken to attack 2 of the benched Charizard ex while Manaphy is knocked out for 2 turns ago and there is no other Manaphy on the match and the Moonlight Shuriken is not working, is this a bug? This happened for 2 times. The Pokémon on his field is 3 Charizard ex, 1 Pidgeot ex and 1 Radiant Charizard.

TechHog

Tera Pokémon have protection from damage when on the Bench. Please remember to fully read cards.