In response, Altrouge set out to put the newcomer Dead Apostle in his place, but by that time Roa was already powerful enough to defeat her instead. Of course, it was only natural. Not only was Roa an excellent magus in his own right, but he was able to wield the power of the strongest True Ancestor, Arcueid, at the same time.

Tsukihime Dokuhon PlusPeriod - TSUKIHIME Dictionary: Roa