If you’re going to try to win before Leticia’s turn ends, you don’t have time for another combat phase. You wouldn’t be able to win by attacking anyway, despite all of the combat tricks you have in your hand: Leticia’s creature base simply outnumbers yours. But she made a serious mistake playing that Ashen Rider, even though it’s not obvious to her just yet…
- Before Leticia’s turn ends, tap three forests and your Golden Hind to add GGGG (two used as generic mana), and three islands to add UUU (two used as generic mana) to your mana pool.
- Spend 3U to cast Griptide on Leticia’s Ashen Rider, putting it on top of her library. Note that the Rider’s ability doesn’t trigger, because it is not being put into the graveyard from the battlefield.
- Spend G to cast Aspect of Hydra on your Wavecrash Triton. Because your devotion is 2, Wavecrash Triton gets +2/+2 until end of turn. Wavecrash Triton is now a 3/6 creature.
- Wavecrash Triton’s Heroic ability triggers. Choose to tap Leticia’s Pain Seer. For what it’s worth, the Pain Seer doesn’t untap during her next untap step… even though you won’t get that far.
- Spend 1G to cast Savage Surge on Leticia’s Pain Seer, untapping it and giving it +2/+2 until end of turn. Pain Seer is now a 4/4 creature.
- Because Pain Seer became untapped, its Inspired ability triggers. Leticia reveals the top card of her library, puts it into her hand, and loses life equal to its converted mana cost. This card is revealed to be her Ashen Rider; Leticia loses 8 life and is defeated.