Sonic Boom (Sonic Fracture)
Armor strip and knockdown in a cone, also works on Acolytes (though they do not get knocked down).

Sonar
DPS boost (Hit marked zones on enemies for a damage boost)

Silence
Supresses Eximus' auras and also supresses Violence's Silence.
Also stuns enemies within range. This stun gets prolonged by Gloom, as the animation is also slowed by 95%.

Gloom
Life steal, but mainly used to slow enemies down within 30.4m of the user by 95%.

Augur Message is the flex slot. Use whatever you like.

This build can be a bit heavy on energy costs, but this is easily fixed by adding more Duration or Energy Max through Archon Shards.

Happy hunting, Tenno!