POB: https://pobb.in/FklzqbDjnEJL

Apparently the projectiles from snipers mark splitting can shotgun with shrapnel ballista and enough projectile speed, so I got a bunch of mark/curse effect and projectiles and some trash gear to showcase it. I wouldn't copy the build as it is since it is a complete glass cannon and if you die you can't finish the boss. Could easily add defenses with more investment to make it actually viable.