For comparison:
Hezrou (CR 11): Str 21, Dex 10, Con 29, Int 14, Wis 14, Cha 18
Glabrezu (CR 13): Str 31, Dex 10, Con 31, Int 16, Wis 16, Cha 20
Balor (CR 20): Str 35, Dex 25, Con 31, Int 24, Wis 24, Cha 26
Klurichir (CR 26): Str 29, Dex 15, Con 22, Int 20, Wis 16, Cha 23
Our current stats put this guy significantly weaker than a glabrezu. I think we need to beef 'em up, particularly Con and Cha.
Good suggestion on adding greater teleport. This guy has very limited spell-like abilities. Perhaps we should give him a few more to tie into his role as guardian?