It could go either way honestly, but I'm kinda hoping for Nightshroud/Darkness just because Atticus doesn't use Red Eyes Darkness Dragon unless he is his Nightshroud persona. If its just Obelisk Blue Atticus it will just be a third normal red eyes user.
Also, from the Duelist Chronicles involving the Sacred Beasts from GX (can't remember the name off the top of my head) there was a "story scene" of Jaden vs Nightshroud from their duel at the volcano. It played a new duel theme for that scene. Plus data miners have found Atticus in the game files but no release date. Atticus is no doubt coming to Duel Links, its a matter of WHEN
Well, he did use his Red-Eyes Darkness Dragon deck in his duel with Zane before Nightshroud took over..
He also used his Red-Eyes deck against Fujiwara.
Obelisk Blue Atticus could use his Sphere Deck from the Manga since lots of Manga Cards are available.
I didn't read the manga so I was unaware of his Sphere deck. Also with his duel against Zane (and correct me if I'm wrong its been a while since I watched it) I remember Nightshroud taking over WHEN Darkness Dragon was summoned. As for his duel against Fujiwara, it was kinda the same he was using Darkness Dragon because of Nightshroud?
Nope, actually he summoned Darkness Dragon by himself saying that this time he'll control the darkness and save Zane. But when Zane activated "Power Wall" and mistreated his deck, Nightshroud took over .. as for his duel against Fujiwara, Atticus didn't summon Darkness Dragon. He only summoned his Red-eyes and Nightshroud did not take control of him.