In every iteration of the timeline shown by Moon=Millenniummon, Lucas and Leomon found themselves alone. Isolated, whether by choice or by circumstance. The timelines where they found themselves the sole survivors of the group were the worst. Bereft of anyone else to relate to or aid, Lucas sunk deeper and deeper into depression and shell shock until, in a few years’ time, he ate the pistol he’d been carrying ever since Beelzemon’s first rampage. Without even a Tamer to give the solitary Leomon any sort of meaning in his life, the last remaining partner Digimon of the group followed Lucas soon after, returning to the Digital World to enact a suicidal charge, fighting aimlessly until he found himself overwhelmed. 

But even the timelines where Lucas found himself with fellow survivors didn’t end well in any sense. 

Faced with the utter mental wreck that was Elle, Lucas simply abandoned her to asylum after dubbing her beyond any possible help. 

Lucas had never had any particular reason to keep tabs on Zei. Thus, when she attempted to kill herself, the attempt succeeded. 

These tragedies hardened Lucas even further, pushing him to ensure that any further conflict between the real and Digital worlds would never occur again. He dedicated the next few years to stopping anyone who would interfere with the Digital World. But the trauma unhinged him, and his methods grew ever more extreme. Eventually, he was exposed and deemed an international terrorist, and fled to the Digital World in exile. 

Timelines in which either Leon or Jordan survived were even more tragic. Lucas and Leomon found themselves forced to kill their former friends with their own hands upon witnessing how they turned on everything they’d fought and sacrificed to protect. 

Siggy had been the closest friend his own age that Lucas had ever made. It only took a weeklong journey through a digital desert for the two to cement their brotherhood, and Lucas had been forever grateful that he’d met one of the most reasonable and reliable people he’d ever known. So when Siggy managed to hold himself together through the aftermath of Moon=Millenniummon, Lucas had been relieved. But circumstances changed. Lucas had ended up as the one to grow ever more unhinged in his attempts to keep peace as the years passed, and when Siggy had stepped in, saying he’d gone too far, Lucas saw red. The ensuing battle resulted in a mutual kill, BanchoLeomon and Examon’s forms dissipating into data as Lucas and Siggy slowly bled out next to each other. 

In the outside world, BanchoLeomon sank to his knees, catatonic.