Question: i have a few of the Fey serie (Treant, Kelpie etc..). Should i:
- keep unevolved for S-Rank (although i don't think they would be much different from carbuncles)
- evolve and keep for low-score S-Rank
- evolve and use as skill-up for the uevo Ogres?
The only ones I've heard being viable are Will-o-wisps and Treants, but you can probably use Kelpie also for Karin subs during S-rank. I don't think anything beat the Feys as 1* for stats, for whatever little they give. I use wisps sometimes.
As for skillups, you can find Freeze Strike/Flame Strike/Rock Strike skillups easier by farming some of the biweeklies or some descends like Hera-Ur where the drop rate for the strike ogres is pretty high. The exception are Pixie and Werewolf, as I've never encountered a place where Jyaki or Shouki drop already evolved, so if for some reason you want to skill those two up, you have no other choice.