User blog comment:FluffySkirmix/Moc update: Can we make Veartax more epic?/@comment-3496744-20110615023209/@comment-2026417-20110615174458

A deuteragonist is one who is either for or against the protagonist during certain points in the story. The Arbiter from the Halo games is a good example, as he was part of the Covenant (which was against the Master Chief) and then formed the Covenant Separatists and allied with the UNSC.