Hello! I was wondering if I could get some help defeating this guy! I was unable to activate any of the seals and can't seem to beat him!!

https://www.sylestia.com/forums/?thread=55951#4
Here, and of course, tips from me (i've been doing this a whole lot now)

First, equipment. Get all your pets epic or above equipment since rare and uncommon don't help much. Give them all TWO accessories. Give Blue Frost a relic that specializes in magical damage, Pickle one that is physical damage, and Holly one that's magical damage.

Second, proficiencies. I would change Holly into Shadow since Pickle is already dealing good damage. and for now, since you're not 60 yet, spend all proficiency points on health.

Third, ordering. Put Holly in first, since when she's switched into shadow she can deal lots of damage and heal herself. Put Blue Frost next, since he can heal the whole party including himself. Put Pickle last, since he cannot heal himself and the third slot is not hit that often.

Other than that, just keep on hitting King D. Hope this helps!