Behemoth

"Erebus: Starless Night. Anything caught in there will die within one minute; simple but powerful. It's not a poison or curse you can defend against; it enacts the concept of death on whoever is caught in its bounds."

No kidding, what the hell kind of spell is this?! It's obviously great magic, but he used it without an incantation again, Fai thought. 

He tried once more to break free from the holds of the quickly-formed cage, throwing a rapid flurry of fists against it, a few kicks, and even a blast of fire--nothing. 

"It's no use. Once you're caught in it, you can't break it."

"Oh, yeah?"

Fai only smiled as if those words from Avdima came as a challenge, only hearing from him "try to break it, if you can", placing his hands together. Even if those eyes still held that same, eternal boredom in their gloomy depths--Fai could tell, whether it be by the instinct of a fellow fighter or his intuition--Avdima wanted him to find a way out.