Combat-wise, Kayelinth and Vampire are the only characters who don't have a stable place in my party rotation. Having Kayelinth round out the last missing elemental spell-slinger is theoretically nice, but for whatever reason, I just cannot buff her MAT high enough to actually damage anything. RIP. I like Vampire conceptually as a berserker, but in practice, she just doesn't do enough damage to justify having a place in my formation. The only situation where she's useful is when her Dark Burst causes an enemy boss to frenzy, but even with really high luck, that doesn't happen that often.