Tanky Melee focused [Valkyr] build.

Requires two Forma for Vazarin (D) polarity slots (or less if you use [Continuity] instead of [Primed Continuity], or don't have everything maxed out).

[Eternal War] as it's a great augment which lets you do massive melee damage for potentially the whole mission on a single cast.
Steel Charge to support Eternal War
Rush / Armored Agility - lets you get to the next melee target quicker.
Hunter Adrenaline - Can be replaced with Rage. Since Valkyr has low shields, this is an almost infinite source of energy.
Streamline / Flow / Primed Cont - Keeps a good supply of energy available. Since you don't cast Warcry very often, I tend to keep this up for Paralyze stuns or emergency heals with Hysteria.
Steel Fiber / Vitality / Armored Agility - for survivability since you'll be in enemies faces all the time