Video: Watch AJ Styles, The OC Attack Undisputed Era and Invade WWE NXT

As Raw, SmackDown and NXT battle for brand supremacy ahead of Survivor Series, Full Sail University had some surprise guests Wednesday.

The O.C. attacked The Undisputed Era backstage before entering the ring and getting into a war of words with Tommaso Ciampa.

NXT delivered the first shot when its roster showed up on SmackDown last Friday, which also came at a time when much of the SmackDown roster was stuck in Saudi Arabia after Crown Jewel.

Adam Cole defeated Daniel Bryan in the main event, and Triple H made it clear NXT was looking to come out of Survivor Series as WWE's top show.

With NXT's move to USA Network, many fans wondered whether stars from Raw and SmackDown would start appearing at Full Sail. Although NXT remains the developmental arm, it's effectively on equal footing now from a broadcast standpoint.

Finn Balor was the first marquee wrestler to return to his roots, which predated the Survivor Series storyline. The appearance of AJ Styles, Luke Gallows and Karl Anderson shows how the door has opened much wider for the main roster.