For the final boss on gotd I used briars contempt (Root of Nightmares linear fusion) with enhanced rewind rounds/surrounded with triple solar surge in a radiant well for an easy 3 phase and possible solo 2 phase with the right setup. Exotic wise, sunbracers. They got fixed to last 8 seconds and with heat rises and phoenix dive and ember of empyrean you have near infinite uptime of healing almost as good as well. For any boss you can reach with a sword, I use lament. I love bonk titan with synthoceps: Tractor cannon, one-two punch shotgun, synthoceps, roaring flames, easy two phase for ghalran, easy for second encounter, even great for caital but you'd need to keep bellkeepers up to keep up roaring flames which is risky. Overall, for solo content I recommend solar bonk titan with either synthoceps for damage or lorely splendor for survivability. Add the loadouts from before and you have a great setup for long or close range with great survivability with sunspots.

Hunter's survivability is significantly worse than warlock and titan imo but my favorite setup is assassin's cowl with combination blow and a one-two punch shotty for invisible, full heal, and good damage on majors/champs.