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.