Mental prisons are the hardest to escape. Lyon's soul has long been jailed by the Demon King's curse, rendering him vulnerable to mind control, and Ivan's psychic powers are perfectly geared towards exploiting that. Long since able to read minds, Ivan's powers have grown exponentially while travelling with Isaac and friends. All Ivan needs to do is nudge Lyon's mind ever so slightly - if he can purge the demon's king control, it should be easy as pie to take advantage of the prince's gratitude and get a quick win in the meanwhile. Ethical? Fair? Just? Nope! Ivan's not so concerned about that, as he has waited over fifty seasons for a single win. He doesn't want to wait another fifty for a chance at another victory.
