I'm fairly certain he only did that in the Japanese version of the game. Regardless, he adopted the last name of his commoner mother, though I forget exactly what the name is. If I recall, he didn't do it to hide the fact that he was a Beoulve, he did it to show that he did not align himself with Dycedarg and Zalbaag.

I'm going to treat that as an adequate answer and go ahead and post a new one.


Of the new Zodiac Braves, which zodiac stone was Isilud (Izlude) aligned with? (Although he never was possessed by a Lucavi.)