Rondo of Swords/YMMV


 * Game Breaker: Izuna can kill the bosses in one hit if you position her correctly. She has loads of hp, she has a skill that gives her the chance to cheat death, AND her attack is extremely high to begin with that she scores 1 hit kill on most unarmored enemies, and leaving armored enemies on their last legs. Also, Cotton; large manapool, devastating long ranged spells, the only mage capable of not dying in one hit to anything, and hyper movement speed, high resistance to magic that she could take lots of fireballs in the face that otherwise kill anyone else in one hit and an OB gauge that fills up quickly and refills both her HP and her MP. Rondo of Swords sure love their crossovers.
 * The ZOC skill, once Margus (and potentially Serdic) learns it. Blocks enemy movement in a game where movement is key to victory, and usually ends with the enemy soldiers all bunched up in an area just begging for an AoE spell.
 * A none crossover example is Ansom. One of the only ranged fighters you get in the game, fairly sturdy, can be recruited early, strong enough to OHKO other archers and mages, a strong Overbreak, and ridiculous range. Best part is that he   can move AND snipe, unlike your enemy archers. This makes it key for shooting select spellcasters that have the equally long-ranged Abyss Gate spell.
 * Needs More Love: The game got relatively good reviews everywhere. But it's an sRPG, it's Nintendo Hard, and Atlus isn't known for large print runs.
 * That One Boss: Mephreyu and . Ernest can be considered one too, in that it's extremely difficult to beat him without losing a couple of men.