I think he might found himself in a similar situation as Miko. Because of his power, he realized the existence of the old man and it realized his existence back, like a sort of Roko's basilisk situation, and he had to find a way to protect himself and his family.
But I'm not entirely sold on the old man being a bad spirit. Could be a Pii situation, the only interaction we have seen is Rohm getting rekt because of his meddling with it. He is definetly the scariest thing to appear though, it's unsettling.