I present, Guts role-player build
Obviously I've got to figure out the armor (thinkin' Fae Royal mixed with some helmet) but for the most part this is the build>! for Guts boy !<sword complete with Behelit Amulet, rapid-fire crossbow, cannon (Meridian), and of course>! the Dragonslayer.!<
Could probably be optimized a lot more but I've been pretty unkillable in Nightmare Boss Rush so far.
Weapon Mods are Spirit Healer on Crossbow, Reinvigorate on Greatsword, and Spellweaver on Meridian with Heatwave on Trinity Crossbow