After The Alliance was disbanded, the WCW World Heavyweight Championship would be simply renamed the World Championship, and later unified with the WWF Championship to form the WWF Undisputed Championship. The Undisputed Championship was originally represented with both the original WWF and WCW title belts, as the champion would carry both belts around, until being replaced with a single belt. At the beginning of the WWE Brand Extension, the champion would appear on both RAW and SmackDown! until then champion Brock Lesnar took the title to Smackdown. Eric Bischoff would reward Triple H with the former WCW championship belt, as he was the last person to have it, renaming it the World Heavyweight Championship. The Undisputed Championship would be renamed the WWE Championship, as having two world titles contradicted the term "undisputed."
Another WCW championship, the WCW Cruiserweight Championship, was rebranded as a WWE title and replaced the WWF Light Heavyweight Championship as the WWE Cruiserweight Championship. Additionally, the WCW United States Championship was revived in 2003 as a "SmackDown!"-exclusive title, thus becoming the WWE United States Championship.
Although the WCW brand effectively died once and for all following the end of this storyline, ECW was "temporarily" revived by WWE in 2005 for the purposes of a special "reunion" show, ECW One Night Stand, held on June 12 2005. The build-up to this one-shot event featured former ECW talent putting over the virtues of the brand versus the WWE product and appearances by several former ECW wrestlers not under contract to WWE. In 2006, it was announced that WWE would be reviving ECW as its third "brand" (to complement "RAW" and "SmackDown!"). The second One Night Stand, held on June 11 2006, led to the official debut of the new ECW the following Tuesday.
Test won the Immunity Battle Royal, which granted him immunity from being fired for an entire year, beginning a storyline in which he would bully other wrestlers simply because he could. Every Alliance member who held championships were also immune from being fired, such as Christian, the Dudley Boyz, and Rob Van Dam. William Regal got his job back by being the first to join Vince McMahon's infamous Kiss My Ass Club. The remaining Alliance members (with the exception of RVD) would associate themselves with Vince, who immediately turned heel, against Austin, who immediately turned face. Kurt Angle remained a heel, despite being the one responsible for the end of the Alliance. It was during this storyline that Stone Cold Steve Austin coined the "What?" catchphrase, which fans continue to chant to this day. Ric Flair would make a return and become the kayfabe co-owner of the WWE with Vince.
The Invasion angle was a large storyline that spanned for almost half of 2001 and brought about financial success for the WWF, such as the InVasion pay-per-view being one of the highest non-major event buyrates in the history of pay-per-views. However, the Invasion storyline has come under criticism by wrestling fans and wrestling media, with the storyline being called a flop. Other media refer to the storyline as "one of the most poorly handled, ego-filled storylines in wrestling history." The Invasion storyline was awarded the 2001 Gooker Award by WrestleCrap for worst gimmick, storyline, or event in wrestling.
Throughout the storyline, many inter-promotional matches had WWF wrestlers winning over WCW/ECW wrestlers, usually cleanly. In contrast, most of the Alliance's wins were due to interference or disqualification. For example, it took Tazz assisting Raven at InVasion for Raven to beat William Regal. The Rock, however, won cleanly at SummerSlam 2001, despite Shane McMahon's helping Booker T.
One particular example of this was during the Inaugural Brawl at the InVasion pay-per-view. Besides Austin's turn in the match that was needed to secure a WCW/ECW win over the WWF, Slam! Wrestling alleged that the Alliance wrestled poorly in comparison to the WWF wrestlers:
""Portrayed as disorganized and inferior grapplers, the ECW-WCW Team had more than its fair share of mistimed moves which hurt their own team members while the "WWF squad" of course wrestled like a well-oiled machines. The weakening of the ECW-WCW dubbed superstars didn't stop there either. The WWF faction battered their enemy tag partners off the ring apron over and over again making them appear weak and more times than not, the ECW-WCW grapplers gained an advantage only by double-teaming or employing underhanded tactics. The message sent was loud and clear. The best of ECW-WCW is not good enough to hang with the WWF.""
It has been speculated that the reason for this was because Vince McMahon did not want the WWF to look weak while fighting the Alliance, as he worked very hard to put down his competition, especially WCW. Smash Wrestling alleges that WWF wrestlers needed to defect to make the Alliance appear to be a credible threat.
The Invasion storyline was presented with a backdrop of a McMahon feud. In storyline, WWF was owned by Vince McMahon, WCW was owned by Shane McMahon, and ECW was owned by Stephanie McMahon. Although the feud did not center completely around the McMahons, the family feud storyline had been done many times before. In addition to this, the Stone Cold versus Vince McMahon feud was to start again when Vince McMahon hit Austin in the back of the head with a chair at No Mercy. As stated by a Slam! Wrestling synopsis of No Mercy 2001:
"For fans who didn't catch it the fifth, tenth or twentieth time they've run the angle, "Stone Cold" Steve Austin and Vince McMahon are about to feud once again... First up was Vincent McMahon labeling Austin with a steel chair as he was waiting to put a dazed RVD away... Three minutes later, it was Shane McMahon's turn to hurl Kurt Angle out of the ring and into a steel ring post. Vince tackled Shane over the announce table and the two began pummeling one another. Back in the ring, Austin laid a "Stone Cold" Stunner on to retain the belt as a disgruntled Vince scowled. Gee, how many times have we seen that scenario play itself out before? Austin wins. Vince fumes. Fans snore. Whatever."
The storyline also allegedly centered too much on the McMahons, who were getting more airtime than the wrestlers.
It has been argued that the Invasion angle may have been more successful if Paul Heyman and Eric Bischoff were perceived as controlling ECW and WCW, respectively, instead of Stephanie and Shane McMahon.
Many fans had dreamed of a day where they could pit WWF and WCW wrestlers against each other, but the storyline's final match ended with four WWF wrestlers brawling it out. As a column in "Online World of Wrestling" stated:
""While it was good TV, it wasn't what everyone thought the WCW vs WWF would have been all about... When the fans of WWF and WCW reminisced about a WCW vs WWF match back in the glory days of Monday Night Wars of around 1997, their match would have probably gone like this: WCW would probably have a team of Hollywood Hulk Hogan, Scott Hall, Kevin Nash, Goldberg, and Ric Flair against... maybe the WWF team of Stone Cold Steve Austin, The Rock, the Undertaker, Shawn Michaels, and Mick Foley. Something like that anyway, obviously, even if Vince had done this thing right and signed some good WCW talent we would have had a match a little different due to... factors such as retirement or injuries or something, but still similar to that.""