| Qaianna |
I'd say as long as it makes sense -- thus, I'd avoid the 1/rage powers (as the unchained barbarian is meant to avoid that whole rage cycling thing). Looking over Abyssal, Celestial, Fey, Elemental, Draconic, Infernal, and Undead, I don't see any there that would run afoul of the unchained barbarian's rules or themes.