I'd planned on Koa'ki from the start. You going lswarm just made it a "Okay, I [I]really[/I] should do this."

Utilized properly, they can be pretty powerful. They've all got pretty nice stats for their levels, and getting Drago and Valafar and keeping them on the field ensures certain doom for any and all meta decks. Having to keep an Iron Core handy most of the time can be a bit of a hassle, but between Diamond Core of Koa'ki Meiru and Koa'ki Meiru Boulder, I'm usually more concerned with getting Drago out first turn so I don't have to put up with the metagame's boss monsters ^_^; the Koa'kis are also gonna finally get some field testing tomorrow, instead of me just beating in AI_Shaddoll.ydk's face in repeatedly, lol.