We're going to need to specify that these can "attach" somehow through a gem purse. Or make the symbiont ability more of an Su thing.
Once a round, a greater peltast can silently use one of its abilities: call monsters (like a monster summoning VI spell, but used to call hostile creatures against its carrier until a good meal opportunity develops); a powerful suggestion (-1 on subject saving throws) to influence called creatures and other beings around them into creating the maximum possible bloodshed without depriving the greater peltast of all potential host-creatures; and Slow on any being touching or carrying the greater peltast.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.