[Rendar]

They're using a bowgun, which means that they're likely Arbie/MG or some-sort like that.

The inherent downside to such a build is that your bow is also a gun. Just dual wield. Use a bow and a gun (likely a sniper rifle). Get the best of both worlds, and still be able to fire the sniper rifle for BBC.

Also, their 'minimum' is still hefty. 50 crit-evade + 25 (bleached fang) isn't much. Then you factor in FAI and LUC, that they didn't even build for, and likely got from aptitude (about 20 or so).

It fits the bill for that. If you want to crit them, you're going to need to have more crit on your bow from weapon mods, and either vamp shell them (to get more crit and reduce their evade), or just spray-and-pray. Your damage, hopefully, should be enough to punch through em.