Milo (Classic)/trilogy.

In Welcome to Forever, Milo and company begin to prepare for their coming road trip, which includes Milo writing as many scripts as he can to turn into Midnight Release and Xiao and Raymond already turning in the art for it. However, just as they finish, Doctor Animo attacks Las Vegas, and for the first time, The Necro Crew is formed as the entire friend group defeats Doctor Animo. However, Milo begins to worry about their road trip as Doctor Animo is a cartoon villain and shouldn't exist.
In Meanwhile EP..., Xiao convinces everyone that their first place to go to is his hometown of Toronto, Canada. The plan was to seek out his aunt, who may have answers, which she thankfully did, but only in so much as it was about The Hyperlane, not Sapphire Blackwood. Milo and Talula take this time to repair their friendship and get closure on the relationship. Simultaneously, Sarah is kidnapped by Murdoc of Gorillaz as he wants to get Sarah to be his drummer. Milo is forced to step up as drummer for Lovecraft Country to battle Gorillaz at 7th Heaven with an Akai MPC 2000XL. In the end, Milo jokingly commented on how the spirit of J Dilla possessed him. However, Russell states Milo was correct, and Murdoc signs Lovecraft Country to his label, Parlophone.
In Never, Never, Land, Milo gets a tip from Malcolm that Milo could get answers from Professor Utonium in Townsville, which he thinks is a joke, but he is shocked to discover that Townsville and The Powerpuff Girls were real. However, when The Necro Crew arrive, they are embroiled in a plot from Mojo Jojo to turn the entire city into apes. After The Powerpuff Girls and The Necro Crew defeat Mojo Jojo, Milo talks to Professor Utonium, who tells him that he can't help him with Sapphire Blackwood but grants The Necro Crew his notes on Chemical X. The compound that created The Powerpuff Girls with hopes that it helps him with The Hyperlane.
In OK Computer, Milo and Xiao travel to Genius Grove alone to chase down another lead that Professor Utonium told them. Here, they encounter an adolescent, Dexter, who has created a company called DexLabs. They are greeted by Computress but are attacked after Dexter's invention goes haywire but specifically hunts down Xiao. Dexter explains that he created the Mysteron AI to discover who came from different timelines after hearing about The Necro Crew's problem. Since Mysteron was attacking both Xiao and Milo, this revealed that they are not native to this timeline. After defeating Mysteron by pushing him into a dead sector of the internet, Dexter says that he knows about the timeline and has dubbed it The Integrated Timeline. He also states that this isn't the first time that people like himself have existed in the same space, but the first time there have been so many.
In Definitive Edition, Milo and Xiao regroup with The Necro Crew, and Sarah discovers a strange energy signal in Breakpoint Valley, Colorado. With no other choice and having nothing else to go on, The Necro Crew travel to Denver, but when they arrive, they discover The DeLorean from Back To The Future and an alternative timeline Milo steps out of it with a jean jacket and a pair of Necro sunglasses. This leads to combat as "Necro Milo" tells the group about his timeline, why he went back in time, and that The Integrated Timeline is inevitable but was created by someone. Milo defeats Necro Milo, albeit barely, and Necro tells his counterpart where Sapphire Blackwood is. When asked why, Necro Milo states that when Milo meets Sapphire, it is the first significant step toward his dark, twisted timeline and vanishes into the timestream with The DeLorean. 
In GO:OD AM, The Necro Crew painfully makes their way to Los Angeles. During the ride, the group talked about The Necro Timeline (nicknamed "Future Imperfect") and Necro Milo. However, they ride in silence when they reach Vegas as all of them slowly begin to realize that their lives are changed forever, and Milo tries to apologize to all of them for involving them. The group denies his apology, stating that they made the conscious choice to do this, and when they reach Los Angeles, Milo and Xiao, injured and tired, stumble to Sapphire Blackwood's front door and nervously knock.