I dunno, I've never used him in battle yet. He's literally like two dungeons behind my characters at all times. He'd probably get killed too fast. Every single one of his stats is lower than Rief's and Rief has better Psynergy. So he's pretty useless, BUT...I just got the second Wind Adept and she's even better than Karis. The second wind chick actually has some fucking HP and strength and stuff. Her Psynergy isn't really as good though, but that's what Rief is for. Once you have Wish/Wish Well, you don't really need Karis.