Talk to the Dark Stranger at 5,3 Plane of Creation to summon semi-private Beasts at the cost of Phials of Vampire Blood. Also summon Osiris for Primal Essences as part of the Weightless Heart Quest.

Commands

/npc Dark Stranger: fbfh - Costs 100 Phials, summons Fire Beast from Hell

/npc Dark Stranger: golg - Costs 100 Phials, summons Golem of Living Gems

/npc Dark Stranger: dac - Costs 100 Phials, summons Prismatic Construct

/npc Dark Stranger: tre - Costs 100 Phials, summons Enchanted Walking Treant

/npc Dark Stranger: mant - Costs 500 Phials, summons Manticore

/npc Dark Stranger: ddoc - Costs 500 Phials, summons Dark Dragon of Chaos

/npc Dark Stranger: give - Costs 100 Phials, 20 Shard Dust, and 40 Crafting Stones, summons ImMoRaL KiNg

/npc Dark Stranger: god - Costs 50 Primal Essences, summons Osiris