FLIP: You can add 1 "Tindangle" card from your Deck to your hand. When this card is Normal Summoned: You can send 1 "Tindangle" card from your Deck to the GY. If a monster(s) is Special Summoned to your field in face-down Defense Position while this card is in your GY: Special Summon this card in face-down Defense Position (this is not optional). You can only use each effect of "Tindangle Intruder" once per turn.
It's like they put two Tindangle cards into DL, then realize they might want to put Akira in as part of Vrains world, so they promptly ignore the archetype and never put more cards in until we have Akira.