In New Mutants #98 a mysterious Arms Dealer by the name of Tyler is first mentioned as he sends Deadpool after Cable. Later, in the Blood and Metal Series, it is revealed that Cable was once employed by Tolliver during his mercenary days with The Six/Wild Pack. Apparently their parting was not amicable. In X-Force #11, we learn more of Tolliver's subversiveness when it is revealed that the Domino who arrived (also in New Mutants #98) was in fact, CopyCat, an agent of Tolliver's sent to spy on Cable, then destroy him. At that time X-Force was residing in an old Sentinel base of Larry Trask. CopyCat's mission was to blow it up after learning what she could. Fortunately, Cable learns of the ruse from Deadpool's loud mouth and he takes CopyCat captive until she shows the way to where the real Domino is being held by Tolliver. To fool Tolliver, Cable blows the base himself and he is off to find his "true" Domino in Sicily, Italy. To borrow a phrase, the shit hits the fan when Cable finds the real Domino and the whole mansion goes up in a fiery explosion in X-Force #15. Tolliver tried to escape in a helicopter, but Cable hung on and shot him down. It was assumed Tolliver was dead because when Tyler's helicopter is destroyed, we see a hat and mask floating in the water and the chase is on to discover the Tolliver.

It is later revealed in Cable #6, through Sinister (among other things), that the man we knew of as Tolliver was actually Tyler Dayspring. All along he had been plotting revenge on those who hurt and used him: his dear old daddy, Cable and that mean old clone, Stryfe. There was one problem. Stryfe was already gone (physically) but his mind was locked inside Cable's. So to punish both the men who ruined his life, Tyler wanted Stryfe's mind to inhabit Cable's body so he could finished them both off.

He gives Sinister vital information he craves and Sinister makes the posession happen with some "frequency" mumbo-jumbo. Meanwhile Askani comes back in time to warn Scott and Jean that Stryfe has returned. She gets captured by Tyler, but has enough time to warn Jean. While a captive, Tyler projects her memories of The Clan Chosen's cloning of baby Nathan and other facts which startle even Tyler. In the finale, Tyler confronts Stryfe with the truth that he was actually the clone and not the original baby Nathan. This apparently sapped Stryfe's will, because Jean and Professor X were able to easily push Stryfe out of Cable's mind. Although Tyler learned more of the truth about his "father", they did not come to peace and Tyler's sanity started to fade.

We next see him in another light as Cable, Domino, Storm and Caliban, venture to Akkaba to investigate a slaughtering of humans. There we learn that Tyler has taken up the mantle of Apocalypse and control over The Dark Riders. He is now calling himself Genesis and he feels it is his inherent duty to continue the practices of En Sabah Nur. He orders The Dark Riders to kill them, but Cable offers an unconditional surrender, if his friends can go unharmed. Tyler accepts and they leave, but not before Cable gives Storm his X-Medallion. HardDrive teleports them away, but with the medallion acting as a homing beacon, the others follow.