And Esta begins the 10-minute casting of Planar Inquiry.
He cannot, by this method, call anything that is stronger than he is -- defined not by who beats who in a fight, or who has more vitality, but by something stranger and hard to measure. Esta would call it strength of life, if outsiders were not dead.
Esta is calling forth an Osyluth, called also Bone Devil, of which it is said that they are hungry for lore of Hell beyond their own stations, and will bargain with it for mortals. Esta doesn't actually have that, and is hoping he can pay with Dark Tapestry transformed items according to at least their price in Merrin's dreamworld. (He did also try asking Merrin for something very unimportant but that wouldn't exist in Golarion, so he can see if the Osyluth maybe values that sufficiently, before Esta resorts to trying to pay with Merrin's valuable device, and then at least resort one of his own two Rings.)