Paxus Asclepius
First Post
From the SRD:
From that, it's open to question how much control the summoner has, but it's dead certain that were the Bearded Devil summoned into combat, it would attack the balor to the best of its ability, regardless of its personal opinions on the matter.
This spell summons an extraplanar creature (typically an outsider, elemental, or magical beast native to another plane). It appears where you designate and acts immediately, on your turn. It attacks your opponents to the best of its ability. If you can communicate with the creature, you can direct it not to attack, to attack particular enemies, or to perform other actions.
From that, it's open to question how much control the summoner has, but it's dead certain that were the Bearded Devil summoned into combat, it would attack the balor to the best of its ability, regardless of its personal opinions on the matter.