Allen also calls the Earl "Brother" when he's all 14th'd out. Cross said that the 14th and Mana were brothers. I think the hinting has become ham-fisted enough that we can say "the Earl is Mana," or at the very least, that there were THREE brothers, and Cross neglected to mention that. :P

The only reason I'm not assuming that Earl = Mana = Earl = Mana is that Allen sure raised someone as an Akuma. I guess the Earl could have made a toy to seem like an Akumana, and given Allen his special eye etc., but that seems unnecessarily convoluted. The simplest explanation as far as I can tell: the 14th, Mana, and the Earl were all brothers.