!!! harmony is better used as a heavy spam build but this is a funny one to use and see the 2.1 billion damage go off
if you want a build for more general use use ninjase's build on overframe: overframe.gg/build/684101/hate/harmony-x2-heavy-spam/
loadout
lavos: any frame works but lavos is used because he's a great weapon platform since valence formation helps with damage a ton, you can use either toxin or electric valence formation, as long as it's a dot. growing power for more strength to increase roar's strength. if using ninjase's build run ready steel which combines with corrupt charge for a 3x combo multiplier.
phantasma: use any primary as long as it has primary dexterity for the combo duration but even then you dont need it.
grimoire: vome invocation to increase roar's strength. amalgam barrel diffusion is nice to have but if you really want to run galvanised barrel diffusion noone's stopping you there just isn't any point since you're not using the grimoire to damage.
harmony: if not using roar make sure to use a faction mod, switch spring loaded blade out for it, or if you dont want to use a faction mod just use killing blow, it doesnt matter too much since damage is super high already.
run dexterity mods on primary and secondary OR run naramon to maintain combo. if you dont want to run dexterity mods or naramon switch out opportunity's reach for gladiator rush/body count.
madurai: sling strength increases roar's strength even more.
diriga: cookie cutter arc coil manifold bond spam. synth fiber and synth deconstruct give lavos status immunity forever. tenacious bond to increase crit damage. you could also run spare parts/medi ray/sacrifice/a different bond mod over primed animal instinct if you dont care about the radar.
vulcax: cookie cutter vulcax build, viral heat for manifold bond with vigilante mods for primary and critical delay to satisfy tenacious bond.