Umbral Servant

Master, Shadow Calling
Level/School: 7th/Conjuration (Summoning)
Range: Close (25 ft. + 5 ft./2 levels)
Effect: One summoned creature
Duration: 1 round/level

You summon a creature of shadow to serve you, calling it through the barriers between worlds.

This mystery functions like the spell summon monster I, except as noted here. You can summon one Huge shadow elemental.