I put my vote to a Forge tbh. Feels like it works best with my slime guy who's likely a magical experiment gain sentience. Additionally I'll probably stick with my slime guy for now since he's the one I feel most strongly for.

As for abilities, I'm thinking that I'll go for the Shadow Class instead. my dude is more of a sneaky assassin type after all, prowling the dark, dropping on his foes. Oh yeah, I'll also go for that Primal Ability over a Core class feature. I like the Sticky Body thing that'll allow me to climb on weird surfaces, maybe even make me better at grappling with my foes once I catch em.

Proto Character build is such:

[b][color=firebrick]Race[/color][/b]: Slime
[b][color=firebrick]Calling[/color][/b]: Shadow
[b][color=firebrick]Dark Impulse[/color][/b]: Paranoid
[b][color=firebrick]Abilities[/color][/b]: Sticky Slime (Racial), Living Weapon (Long Reach, Grappling) (Flexibility)
[b][color=firebrick]Dungeon [/color][/b]Type: Forge