When Vittari met Kardin, the latter appeared as an aged human with a trimmed white beard in a room of white. He was not unattractive or beautiful. Is this what he really looks like? Good question.
Speaking through ethical and philosophical queries, Kardin seemed nonchantly, almost uncaringly impatient when he spoke to Vittari after the latter had managed to locate Kardin’s realm. Upon jumping into one of the gates Biagio and Tallus have been closing, Vittari promptly entered someone else’s body. He saw a brick wall floating in the horizon and managed to reach it after pulling down a tapestry that had been on the ceiling of the building he was in. (Yes, somehow he saw the horizon through the ceiling and the tapestry.) Once he’d reached the wall, Vittari found himself in a white room where he was greeted by this man identifying himself as Kardin.
Kardin offered Vittari very little in the way of answers, except that he had known the Bone King. Still, it was very clear that Kardin was somehow intimately important to the goings-on troubling the Material Plane.
Earlier that same day (though later in real time), Kardin also spoke to Aidan and Tallus via a communicative ritual the two of them completed upon investigating the gates opening on Ern and Elmsville. Once again, Kardin offered little in the way of answers. He said he didn’t know anyone named Adonis but that the gods had imprisoned him. Again, he asked a number of philosophical questions even as he encouraged the two PCs to think very carefully about who their real friends were.