The Demon King Bloodline, although extremely powerful, also connected the Bloodline holder to HELL itself. If a Demon King stayed away from HELL for too long, then they would lose their Demon King Bloodline permanently. For regular Demons, this meant something worse than death, which was why, even if they found a way to leave HELL, they would prefer to never leave.
For Cassius, however, losing the Demon King Bloodline wouldn't be the end of the world.
That wasn't to say he would allow it to slip from his grasp, but he also wouldn't die for the chance to keep the Bloodline. Yet, in this case, he was nearly ready to head back into HELL.
With months until the deadline, he was confident that he would become strong enough to confront the weakest of the Demon Kings on the 1st Floor of HELL…
—Time passed gradually—