Ki is Antony's companion demon. Companions are created with Round Masters, a low level demon as a sort of first test. However once the Master has others to care for the companion is seen as a weakness and they either meld into the human world or die. Ki chose to meld by opening a tavern and inn, and swore that he'd wait for Antony to return to him, even if his Master had become a cursed Keeper. He waited centuries there.