EXP nerfs in the current KMST Patch.

A xenon funded with equips obtainable without money can do this.

Even assuming you can provide some evidence to back up this statement, you'll have shown that ONE class out of more than 30 can achieve it. One (relatively) overpowered class does not a balanced or good game make.

Also you'd do well to remember that a "normal" person does not simply merch their way to 10b+ without spending money on the game (and that's generously setting the bar REAL low on the amount of funds it would take to achieve that kind of damage).