Additional Steps Required

Need to use some form of armor stripping (like [Shattering Impact]) on the boss to strip 100% of its armor and turn it to Fossilized to unlock full damage potential +50% damage from Corrosive

Arcanes

Arcane Merciless - mostly for reload speed increase
Arcane Deadhead - if you struggle with recoil. Combined with Steady Hands will give you NO Recoil

Warframe Synergy

Vigorous Swap - godly additional damage
Arcane Awakening - trigger by reloading during the boss walk phase for +150% damage (might need to reload a couple of times to trigger)
Arcane Velocity - Massive DPS increase in the form of additional fire rate.