They possess a phase shift support field. All allied ship's weapons inflict more damage to armor and less to shields by reducing the target's shield defence by 25% multiplicatively.
They are seen amongst high level fleets, although not as prevalent as Ragnarok carriers. They are most often seen escorting destroyers.
Strategy and Setup
It's phased projectile field ensures more direct damage to the enemy's armor.
Most players choose to build the Valkyrie carrier for its unique support field. With its phased shifter field, combined with phased projectiles, innate shield bypass from battleships or destroyers upgraded through the crafting system, it can inflict a substantial amount of damage to armor and ignore shields. This reduces the time to eliminate lightly armored shields.
The carrier at MK1 can be equipped with four Bomber Squadrons III, Metaphase Shield III and Fusion Thrusters III or Rear Thrusters V making it ready for high level combat unlike the Valhalla carrier which needs an upcraft to MK3 for the same configuration.
Obtaining crafting materials for the Valkyrie carrier is very difficult as there are no supply run fleets.
The Valkyrie carrier isn't as popular as the Ragnarok carrier because the phase shifter support field is aimed at specific fleets and combat strategies. The agility support field of Ragnarok has more use in PvP, events and fights against VEGA fleets.
Usage by VEGA
This carrier was introduced by VEGA for use in VSec Regulator fleets starting in Face Off, after they decided to stop using their Ragnarok Carrier, but not until the rebels stole the Ragnarok Carrier's blueprints and obtained the ability to build them. They reappeared in VSec Detachment fleets during Reclamation.
VSec variants of the Valkyrie use a stasis field, not a phase shift field. Your ships will have inhibited movement speed, rotation and strafing when within such a field.
The Valkyrie Carrier was first featured in a video months before the event, seen in the KIXEYE Youtube Video around 0:32-0:33 featuring two scenes of the Valkyrie Carrier in combat.