Reign of the Shattering Void, Let There Be Light!

...

A few moments later, Izroth, Lances, and Zel'Kan were joined by the rest of the 9th Division and 5th Unit.

By the time Zel'Kan and Lances reached Izroth's location, Marquis Varokin had long vanished without a trace. And, after seeing that Izroth was unharmed, the three wasted no time returning to where their allies awaited.

But just as the three of them started to make their way back to assist the others with the Undead Night Marchers, their forces, led by Niflheim and Noir, had already made their way over to them.

Apparently, just seconds after Lances and Zel'kan departed, the Undead Night Marchers abruptly turned to a cloud of dust and disappeared.

Based on their account of events, Izroth determined that the sudden disappearance of Marquis Varokin coincided too closely with that of the Undead Night Marchers for it to be a mere coincidence.