Nexoria: Dungeon Rogue Heroes (US)

I got this doing Hardcore mode. Level 4 is Ice Palace. Just use the Ice Mage and make sure his special is called “Throwing Icicles.” If it’s not, change the appearance and the spell should match. Use it on an enemy on this level and it should pop.

-The Ice Mage has an ability -Throwing Icicles-. Use this a few (or many) times, until the enemy stucks into an ice cube and this will pop. Could take a couple tries.

EDIT:
-You can also use Knowledge on a Mystery Scroll to learn a Freezing Spell (looks like an ice cube). Or you can happen across an already Frozen enemy if you are on a floor that has the Ice Palace terrain.
thanks to VidGamiac

Not sure, if there are other ways, to obatin this.. lmk in the comments.

1. You need to chose the ice mage
2. You need to cast "throwing icicles" spell

You do not need to do this on hardcore (but you can if you are trying to knock that achievement out at the same time). I did this on normal. I am 99% certain you must do this on level 4, the Ice Palace. Otherwise it just makes the enemies wet. I got this the very first time I cast the spell on ice palace, after casting it 30+ time on level 1, 2, and 3. (Don't forget to save and quit after each boss, and then continue just incase your game crashes, or you lose your ice mage)