To nitpick, a henchman or hireling is by definition subservient to one or more party members, in an employer-employee kind of relationship (and is usually paid by same, rather than getting its own treasury share). Adventuring NPC, or just "NPC", better defines a non-player party member that is considered equal to the others.I wouldn't throw around the term GMPC when NPC will do nicely. It's an NPC cleric. A "henchman," "hireling," or "adventuring NPC" if you will.