Malevolynx

Malevolynx is the corrupted form of the legendary hero, Leonyx, and the final boss of Dragon Quest Monsters Joker 2. Once the island's savior it is now an enraged monster that's putting the island and its inhabitants in peril. In both forms he looks like a behemoth humanoid lion that wields a pair of giant swords. When Malevolynx, his mane and fur are white, has red eyes and his armor appears made of silver, probably to look more like a lynx; in his normal form he has yellow fur and his eyes appear normal. Eventhough the player can get Leonyx via synthesis (though it's one of the most complicated-to-synthesize monsters in the game), this evil form is not obtainable in any way in this game, but can be in the Professional edition (only released in japan).

The source of his evil power and the main reason of the island's demise is an even more powerful foe.

Abilities
This boss can attack twice per turn and three times when he's at the verge of defeat. It has the most powerful magic, breath attacks and strength so far. Perhaps its most deadly attack is his lightning storm.