It was evident that Tristan had now transformed into Shael.
Normally, deities cannot descend at will; they need an anchor point.
For example, a divine idol imbued with the power of faith, previously the Rose Spider Queen had descended through her own idol, and perhaps the other three goddesses were able to descend simultaneously with the consent of Rose.
The second type is a fiercely devout follower; Laine's Supreme Decree could entreat the Lord of the Dawn to cast his gaze, a might potent enough to destroy half of Alchemy City.
The third type is a special divine artifact, like the gold coin given to Amberser by the God of Alchemy, this artifact enables constant contact with the God of Alchemy, allowing him to descend.
That black dagger must also be a special artifact prepared by Shael, hence her ability to descend into Tristan's body.
When faced with Shael's interrogation, Amberser remained incredibly calm.
