A quick epilogue for The Invasion:
The Raw after Invasion:
Vince McMahon: Back to full blown heel authority figure, even though the WWF was the face side the night before and he ended that show triumphant.
Mick Foley: Quits in a cold opening on Vince's plane because he felt he was underutilized and his role was redundant with Vince on TV.
Kurt Angle: Started the angle as a comedy heel, turned comedy face, turned super intense top babyface for the Summer, immediately went back to comedy face, then turned heel and joined the Alliance, but turned face at Survivor Series revealing he was a double agent so his previous heel turn was all a ruse to disrupt the Alliance from the inside. Turns heel for real on Raw because no one but Vince appreciated what he did for the WWF.
Dudley Boys, Test, RVD, Christian: All were carried over for being champions, except for Test, who won an immunity battle royal. Vince hates them all, holds them being in the Alliance against them, punishes them. RVD was put into a handicap tables match against the Dudleys.
William Regal: Rehired for literally kissing Vince's ass in the middle of the ring.
Ric Flair: Debuts as the mystery person who bought Shane and Stephanie's WWF stock, making him 50/50 partners with Vince. Vetoes Vince's plan to strip Austin of the WWF Championship and hand it over to Kurt Angle.
Steve Austin: Immediately turns face, hits Vince with a stunner, drinks beers with Ric Flair.
The Smackdown after Invasion:
Ric Flair suggests unifying the WWF and World Championships at Vengeance, Vince concurs but wants to make it a mini tournament, both agree to terms and competitors.
Undertaker: Starts his heel turn because he was mad Vince didn't respect him enough to let him know Kurt was a double agent or be asked to be the mole himself.
Austin is doing full blown comedy with Regal, Regal/Test/Dudleys/Christian give Austin a beat down at the behest of Vince. Later in the show Vince celebrates with them and says they're like family, then gives Christian an IC title shot and the Dudleys a match with Rock/RVD that ends up being a handicap match with Jericho added.
Tazz: Rehired by Vince off screen for choking Heyman out the week before, still a heel, will be a competitor and announcer.
In short:
Vince, Angle immediately turn heel. Austin immediately turns face. Ric Flair comes in as 50/50 owner and they again have dueling face/heel authority figures. On Raw Vince hates the remaining Alliance guys and punishes them, on Smackdown he loves them and gives them preferential matches. Undertaker starts a heel turn where his issue is with heel Vince but he ends up taking it out on people like JR. The main core of Alliance guys minus Booker are still on TV anyway. Booker is hired back by Vince to go after Austin. Lance Storm gets hired back by getting odd jobs at venues they were running TV (what are the odds) and getting himself into matches where he'd get a contract if he won, and he ends up getting a countout win over Rock to be rehired. Everyone else (DDP, Hurricane, the ECW guys) either just kind of popped back up, trickled back on the C shows, or were part of the original brand split.