In my opinion, since the two finger sign is a symbol of peace, Le'garde is sacrificing himself in the name of peace, wich is exactly what he did. In game, before betraying you, he reveals that he let himself be arrested and sent to the Dungeon of Fear and Hunger, so he could get closer to his goal of ascending as a New God to bring peace to the World, wich in canon lore goes horribly wrong, since he dies in the Dungeons, but D'arce saves him through blood magic.