Mysteries of Immortality?

What was behind the gate?

'Mecantron', the Angel King who was standing on the other end of the Pathway of Immortality, also asked himself. What exactly was the mysteries of immortality that so many experts tried to touch?

Rudolf II, who had already turned into 'Mecantron', did not bother with his current form. He narrowed his eyes and thought to himself, "After I learn the mysteries of immortality, I'll find a chance to kill Lucien Evans and Rhine Carendia. I don't think that the Silver Moon can arrive at this place."

The mysteries of immortality obviously could not be shared!

As for why he did not attack the two of them immediately, Rudolf II was certainly glad that somebody eliminated dangers ahead of them. Who knew what was behind the gate of immortality?

What was behind the gate?

The Lord of Hell, hiding inside the Pathway of Immortality in a weird form, looked at Lucien and Rhine up ahead and the 'Angel King' nearby, and asked himself.