Exoffus hadn't forgotten about Alister since he and those two human traitors were watching Alister's battle against the Tentacle Saint while they were in the dimensional gap.
Since there were only a few Transcendent Saints in the human race, Exoffus couldn't forget Alister, the Fourth Transcendent Saint of the Human Race whose title was proclaimed by Alister himself as the Sword Saint.
Exoffus was the Third Transcendent Saint of the human race and he greatly attached importance to those who could become a Transcendent Saint since they were a powerhouse that the human race badly needed.
The first time that Exoffus encountered Alister, he knew that Alister was someone who was decisive and would only do things that he was certain of. He also noticed how cautious Alister was when Alister didn't expose his power to save and prevent Margaret from being raped by that tentacle monster.