The Arcane Green Lantern is Sir Harold Jordan, a highly distinguished member of the Order of Emerald Knights who was saved from the Black by Emerald Knight Alan Scott as a small child. Arcane Green Lantern is charged with keeping an eye on the creatures that spew forth from the Black, which was opened by the Shadow League.
This new Champion will officially be added to Infinite Crisis‘ roster on September 16, 2013. The game is still in closed beta, so if you want a chance to try out the Arcane Green Lantern you can sign up for the beta here. While you wait for his release feel free to check him out in action via the new trailer and screenshots embedded after the break.