In the final years of the Endless Night, Somnus had been blighted by the Scourge and made to wait to fight the Chosen King. In the pit of that darkness, there was some shreds of his soul remaining, some knowledge of who he was, of what his principles were. But, again: the amount of time he had spent cursed is nothing compared to the millennia Ardyn had endured-- and still endures.

Still, he wonders, just how much does the Scourge control him, how much remains of his brother? In choosing vengeance, he chooses despair sustained by immortality and harms himself further. That is part of the curse. Perhaps he has not recalled that he's already won, by the Bladekeeper's prophecy, at that. Ardyn's revenge upon Lucis, the royal line, and the world, is fulfilled.

Somnus' head tilts, and he eyes the tip of the blade pointed at him, frowning.

"The gods chose you to house the Scourge... but you did not deserve to be their chosen."