He aspired to ascend as a Heavenly Immortal, which required severing all current ties, then undergoing reincarnation to start anew as a mortal being.
From this perspective, he was a "negative" on the Immortal Path, having lost his Dao foundation, making him lesser than an ordinary person.
To ascend to the Demon Realm of another domain, although the methods of cultivation had similarities to the Immortal Path, they were fundamentally different; he could ascend like the Elder Blood God, or become a Devil's Child and Grandchild and be directly captured, or he could enter a Demon Scripture to rule for a thousand years before departing.
