I checked and indeed; it is symbol of malfeas on his forehead then. But still it would not tell what he is exactly besides he has glowing brand on his head but he said he is exalted like you and he is correct. But so far there are no records of primordials having 'exalted champions' expect akuma. But there is conflict here; as akuma would not had opposed demonic army at all but rather helped it take over the city. But you do know even akuma showed traditional signs of their normal exaltations; solars anima banner and symbols were same as they were before they dammed themselves. So Belar could be considered a curious enigma. Also it was true that he is not sure what he is but he knows what demons know him to be; a green sun prince, champion of malfeas, sword of hell, infernal, a slayer. But the deeper meanings of these are not clear to him as he has not gone to the mandatory visit on malfeas which should occur sooner or later as loom of fate will eventually detect his presence (but I guess this massive demon army distracts exact readings of his presence so he got extra time to linger before he is educated thoroughly what for he was exalted. So once army is gone he is likely chased by sidereals to nearest gate to Cecelyne's desert asap if not actually retrieved by senior green sun prince).