Herc offers quite a lot more spike damage though. I'm still not really convinced of the ATK Shingen weapon, since you kinda trade Hercs nuke for an ex skill, which often might just be ambush (which Hercs burst effect already covers). If you really need the ex slot, then that might be a different story, but f.e. for fire, there's just so much damage potential in Herc + Amaterasu, Mars, Svarog, Uriel/Ares and you're really not gaining much by running Shingen, except for some more flexibility. Either way, I'll most likely get both the Herc and Shingen ATK weapon and then try them side by side. Hard to judge without actually trying them in action and I don't really see any other good options for fire atm.