The Infinite War is the basis of the plot of Fighters of Lapis 6: Brotherhood, World War X, Tower of Ungodliness and the "Infinite War" story mode in The Mysterious Seven Project. The war initially raged on for ten long years and it surrounded the Infinity Gems of the Infinity Gauntlet.
To understand the history of the The Infinite War, we must go to the end of time in the Lapisverse. This is where the war truly begins, even though it doesn't happen for negative billions of years.
THE LAPISVERSE SIDE OF THINGS
Twilight Sparkle is born at the end of time and begins moving backwards in time.
Tabuu summons the Brotherhood and heads out to find the Inifinite Gems with Thanos’ help. The Fighters of Lapis fight the Brotherhood but loose, resulting in the breaking of the minds of Luigi and Batman. Batman recruits the help of Don-Chan, Mako, Player, Marceline, Homura, and the other starting characters in Timeline 2.
Meanwhile, Mario, Robin, Homura, and other Fighters of Lapis take on Promixa Midnight and her army of Subspace at Delfino. Robin devises a strategy that seems to work; it doesn’t, leaving just Mario and Homura alive. Homura creates a new timeline by fixing Robin’s plan, dooming this timeline.
Batman goes to the other timeline and recruits some of the people he seems to recognize as a rag-tag team. He eventually regains sanity, but realizes he is in another timeline entirely and enlists the help of Rick, to figure out where the current Mario is. Batman marked Mario with an X before he went insane without Mario knowing, but Rick can’t locate him for some reason.
Homura goes back prior before doing the battle at Delfino, creating the first failed timeline. They win the battle, and Homura begins to discuss the consequences of failed timelines. Since they are in a war, it will be nearly impossible not to create failed timelines as the result of their actions.
THE MYSTERIOUS MYSTERIOUSVERSE'S INVOLVEMENT