Using "Dragon Aspect" I captured the soul of a seeker and it drew a supposed Ancient Dragonborn Aspect from some Plane of Oblivion. See Watch, This is a stock ps3 with no mods, and i have not heard mention of this anywhere.
With two of the words for Dragon Aspect when you health hits 50% while using the shout a "Ancient Dragonborn" will be summoned. The Dragon Priest Mask Konahrik has a similar effect but it will summon a Priest to aid you.
There is a section about doing both on his page and the treasures page but to edit a page click the black Edit button (with the little pencil) next to the page title or to suggest a edit click the grey Talk button next to that.