Would I level up Sonya or Grimm first
Grimm! His defense down special skill is really valuable for titans and offensive raids.
However, it is a close call and I’d definitely make sure to level up Sonya asap as well because of her buff dispelling.
What does the rest of your team look like?
Sonya is more defensive. Higher defense stats and dispell buffs, shes good for that. Grimm is aggressive. Fairly high attack stat and reduce defense. Grimm is all around better I would say, personally. Sonya won’t kill with her special unless the hero is already quite weak. Grimm is a real hitter. Caedmon is better than Sonya as a dispeller.