If you target a face-down Defense Position monster, it is flipped into face-up Attack Position. If you flip a Flip monster this way, its Flip Effect can activate.
The Trigger Effect of "Blackwing – Elphin the Raven" targets the opponent's monster.
You can target a face-down monster with "Blackwing – Elphin the Raven" and flip it to face-up Attack Position. If the monster has a Flip Effect, it will activate.