Twilight Ninja Nichirin, the Chunin [MP16-EN187] Common

Once per turn, during either player's turn: You can discard 1 "Ninja" monster, then activate 1 of these effects; •This turn, "Ninja" monsters and "Ninjitsu Art" cards you control cannot be destroyed by battle or card effects. •1 "Ninja" monster you control gains 1000 ATK until the end of this turn.