Operator Arcanes
You're limited to two Arcane slots, so what you want to take will be down to personal preference.
Some Recommendations:
Magus Lockdown: Helpful Crowd Control - can keep the Operator safe from trash while killing Spectral Forms, and useful to quickly lockdown an Acolyte spawn.
Magus Cloud: Widens Void Sling radius to help with quickly clearing Void Tears on possessed Exolizers. Be aware of anti-synergy with Onslaught if you're replenishing energy by slinging through enemies.
Emergence Savior: Death prevention for the Operator. Helps to keep you safe from trash while killing Spectral Forms or self reviving with Last Gasp.
Magus Anomaly: Helpful for grouping, particularly for melee focused builds.
Emergence Dissipate: Energy replenishmen for those comfortable using it.
Magus Melt: Additional Heat damage on the Amp, but be aware that this will only help with Last Gasp and shooting the central part of an Exolizer after the tears have been cleared, as the Heat damage has no effect on Spectral forms.
Magus Elevate/Nourish/Repair: Warframe healing, though these will not be helpful once you're beyond the point of health tanking being effective.
