Yeah sometimes it takes forever for them to drop in those dungeons.
I decided I was going to do the light mechdragon on technical master. I only had to spend one stone, on the evolved chimera fight, when the bastard bound my light ripper for 4 turns and completely disabled my 50% light damage reduction, then one-shot me. I figured I had gone that far and couldn't really go back!
My team is my holy light ripper, an evolved Lilith, a rainbow keeper (that eats up a TON of cost but it's saved my life more than once), my green ripper (because you always need 20k more damage!) and a Myth-dublit because, well, it has a 1 cost and I had 2 cost left after the rest of my characters.
In retrospect I could've probably better spent the cost from my lilith, which as awesome as she is, is not *that* useful in this dungeon. My echidna would've probably served me better.
Those damn harpies are stupid annoying, though. Hit hard, on a one-turn timer, and can bind all my dark? Ugh.
I'm on the 9th level fighting 2 light carbuncles that can heal themselves. Can they heal themselves more than once?