When a face-up "Blackwing" monster you control is destroyed by a card effect and sent to the Graveyard (except during the Damage Step): You can Special Summon this card from your hand. When a monster is Synchro Summoned using this card as a Synchro Material, the opponent of this card's owner cannot activate cards or effects.
It's one of the few worth at least thinking about. Shame we didn't get Cheepcheepcheep to go along with it, though, as that's what makes it decent. (Or Battle Tuned, but that would probably be a little absurd here.)