WWE's pay-per-views are where rivalries escalate or culminate. While the current pay-per-view schedule is intact, there are some classic shows fans will never forget. Some of these shared classic moments during the Attitude and Ruthless Aggression Eras; such as new faces, championship victories, and historic Hell in a Cell matches.Here are five former Pay-Per-View events that should return to WWE.#5 WWE No Mercy| FULL MATCH |A new chapter is written in the rivalry between @BrockLesnar and The @undertaker with the #WWETitle at stake in a Biker Chain Match at WWE No Mercy 2003: Courtesy of @WWENetwork.👀 https://t.co/AMuiCjijKl pic.twitter.com/OTDloy2whj— WWE (@WWE) July 17, 2020Wrestling fans saw Kurt Angle win the WWE Championship for the very first time on this pay-per-view. When the show returned in 2016 and 2017, WWE proved that the event could still deliver. With stacked cards and match stipulations, everything was game.In the last WWE No Mercy, Roman Reigns defeated John Cena while Brock Lesnar retained his Universal Championship against Braun Strowman. The retro pay-per-view was so significant that WWE named one of its legendary video games after the event.For some historical facts about No Mercy, a match involving the WWE Championship was once an opening match back in 2016. The outcome was AJ Styles successfully defending his championship against Cena and Dean Ambrose in a triple threat match.Brock Lesnar also has a unique statistic at No Mercy. Lesnar has a win-loss record of 3-0. For every No Mercy that Lesnar was part of, he would be involved in championship matches, whether the WWE or Universal Championship.Lesnar retained the WWE Championship against The Undertaker twice in back-to-back No Mercy's from 2002-2003 in a Hell in a Cell and a Biker Chain Match. Lesnar also retained his Universal Championship against Strowman at No Mercy 2017..@JohnCena aimed to unseat @BookerT5x as #USChampion in the final match of their Best-Of-Five Series at No Mercy 2004! #SummerOfCena https://t.co/d1b9iKlhGF pic.twitter.com/m8qkxdgidq— WWE (@WWE) August 15, 2021If No Mercy were to return, it could take place in October. WWE could use the show before one of the most significant pay-per-views, the Survivor Series. The show could also feature new rivalry matches now that the draft is held in the latter half of the year.