The Horn of Valmar...whatever. It's not like Ash is any stranger to fighting peculiar demons. Melfice is pretty damn tough, and packs one hell of a punch...pity that Ash, as a Vandalier, can take more hits than a brick wall and does plenty of damage himself. Melfice's usual bag of tricks won't do much here, as Ash can shred through his HP before he can really get going. His array of various stat buffs, healing moves, and other magic abilities just gives him even more of an edge against Melfice. Even if Melfice lands a hit, and that's by no means a given considering Ash's evade, he'll have to get lucky more than once, and sooner or later, his luck will run out. Ash doesn't need luck, just the power of the Vandal Heart. And that's what's going to see him through this match, and all the matches to come.