The idea is that as Egoists gain more physical power, their body transforms into something that less and less resembles a human being. It's a permanent and gradual transformation that basically makes it impossible for them to reproduce, unless they're a weirdo Egoist who specced their body specifically for that shit. As for the wildest stuff...

At the highest levels, and at the risk of fatal Abstraction, Egoists can take on the form of building-sized kaiju temporarily (if they were martial-focused Egoists). Their regular form would just be a smaller, perhaps more humanoid variation of their kaiju form. Even in those regular forms though, battle between two Egoists would basically have them pinballing all over the place and cause copious amounts of environmental damage with each exchange...but thankfully, those that make it to the highest levels are also mature enough not to unleash their full power, especially during peacetime.

During the start of the Futile War between the Occident and the Orient, the Occident was forced to acknowledge that the concept of infantry was absolutely worthless in this 'new' era, as mere mortals were basically like pieces of paper caught within a storm when Egoists took the stage. Literal Dynasty Warriors shit, except the Dynasty Warriors also have speed cheats on.

Your average martial-focused Egoist could pull off this shit in their 'fuck yea' moments. Sending elephants flying n all.
[youtube]https://youtu.be/6_EKmrURNyc?t=666[/youtube]