Each of the colossi had a fragment of Dormin's spirit. Killing the colossi freed all the trapped fragments. The shaman shows up just as the last statue in the hall crumbles. You pop in looking like a zombie and the shaman has one of his men stab you to put you out of your misery after telling you that Dormin conned you. At this point, dark energy sprays out of you and envelops you and Dormin possesses you. The shaman takes the sword and flees and you get to play as Dormin for a bit. Once the shaman gets to the exit he throws the sword into the spring at the bottom of the stairs. It sucks all the dark energy in (including you) and destroys the bridge as the shaman and his men ride back across it. The girl wakes up and Agro hobbles up the stairs to join her.
As the credits roll, the shaman stops and talks about how no one can get to the area now that the bridge is gone and says that if you survived somehow he hopes one day you can atone for your actions. (It's believed that this is a direct allusion to Ico by some.)
Post credits, the girl and Agro go to the spring and find a baby with horns on its head. They take the baby and climb up to the garden on top of the temple.
The end.