Wait, I was rereading and then I noticed Ali-san's name which is Alikred, is just the name of the former Demon king Derkila but backwards, so is this man the soul of the former demon king, or this is just a mere coincidence? I still believe that Ali-san and the former Demon king are somewhat connected. Also as
@Tuffin said,
why did Sullivan avoided the question and insists that it can't be conscious ? Derkila also appeared before Iruma saying "So, it's you" to Iruna when they made the Legendary Leaf grow what did it mean?
Gosh, I can't really wait for further chapters