EDIT: After the latest staff reply, I did a quick search and found the earliest theme submission that is almost a perfect match to this shifter/summoner hybrid concept:
There were earlier mentions of lycan/werewolf themes but none that combines it with summoning/minions. The above is clear enough to convey the exact theme; what follows is a draft/fleshing-out of this idea.
My concept - copied over from the Fan Concepts sub-forum (thread). The theme is a hybrid between a summoner and a lycan, where the shift morphs the frame into an exalted melee-form direwolf, which is upgradable and comes with it's own stance.
[Warframe Concept] Morrigan - Lycan Shifter/Summoner Hybrid
"The Morrígan or Mórrígan, also known as Morrígu, is a figure from Irish mythology who is mainly associated with war and fate, especially with foretelling doom, death or victory in battle. In this role she often appears as a crow, the badb. She incites warriors to battle and can help bring about victory over their enemies. The Morrígan is often described as a trio of individuals, all sisters, called "the three Morrígna" Badb, Macha and Nemain (war personified). As a shape-shifting goddess, she has taken the form of many animals including a wolf." [revised citation, source]
This warframe is meant to be a hybrid between a summoner and a lycan, where the shifted body itself is an exalted melee-form. I've taken a few liberties with the lore.
SHIELDS HEALTH ARMOR
Initial/Frame Form: ✖️ ✔️ ✔️
Split/Raven-Frame: ➕ (ravens) ➗ (ravens) ✖️
Lycan Form*: ✔️ (sacrifice cap) ✔️ (sacrifice total) ✔️ (sacrifice cap)
(*Plus 1 trait-sacrifice)
Passive (Swan Song): Each ally death will replenish 10 health to all allies in a 20 meter radius.
When starting out, Morrigan has no shields - just her health and armor.
Ability  - Raven's Call - consumes energy, toggled, not channeled
Morrigan drains her entire health pool (-2 pts.) and manifests her life-force as a flock (an unkindness) of ravens. Each raven will grant Morrigan a fixed X amt. of shields.
- The number of ravens are affected by ability efficiency
- The ravens are not classified as allies, they are not targeted by enemies
- The ravens do not have armor, but are invulnerable while Morrigan has shields
- If Morrigan's shields are completely depleted, any further damage will be split among the (unarmored) ravens
Recasting/toggling-off: will break Morrigan's shield, drawing all the ravens back, replenishing her with their remaining health instantly and now makes the frame's armor effective.
- When toggling-on the shields will always regenerate starting from 0
- Health regeneration (via arcanes, consumables ..etc) is not possible while the health pool is manifested as ravens
Ability  - Foretold Sacrifice - consumes energy, not ready without any ravens from 
Morrigan marks an X number of enemies for the ravens. When you or an ally kills a marked enemy, a raven will collect an X% of their health, with Y% armor or Z% shields.
- These sacrifices are used to feed/craft Nemain (Morrigan's lycan form)
- Marked enemies receive a flat -33% accuracy (only) when targeting Morrigan
- Toggling-off  will remove all active marks
- Lesser-wolves will prioritize marked enemies - breaking engagements with unmarked enemies (if need be)
- % bonuses are affected by ability strength
Hold-to-cast (consumes energy): will heavy-mark only a single special enemy for a trait-sacrifice which extracts a weaker version of it's aura/ability as an offering. For example, the aura of an arson eximus, which Nemain will receive with less effectiveness.
- Recasting for a trait-sacrifice will replace the one which was previously extracted as an offering
Ability  - Pack Hunter - consumes energy, channeled
Morrigan or Nemain casts an aura which multiplies (only) their own damage and attack speed based on the number of allies within the aura radius. These do include lesser-wolves but not the ravens (nor any spectres, Nekros' shadows ...etc).
- Aura range and multipliers are affected by ability range and strength
Ability  - Lycan's Call - does not consume energy, toggled
Morrigan breaks her shield and draws all ravens (if  is toggled on), and shapeshifts into the direwolf Nemain. Nemain is an exalted melee-form with her own stance.
- Health/Armor/Shields are based on the total sacrifices collected, including the last collected trait-sacrifice (aura/ability)
- Abilities  and  cannot be cast in this form - but ability  can be toggled on and off
- Recasting will morph Nemain back into the exact state Morrigan was just before the cast
Hold-to-cast (consumes energy): will summon a pack of lesser-wolves each having a fixed X value of health, Y value of armor, and deals only physical damage.
- The lesser-wolves are classified as allies
- The number of lesser-wolves and their stat values are affected by ability strength
- Both Morrigan, and Nemain as well, can hold-to-cast
- Repeating a hold-to-cast will only summon lesser-wolves upto the max. total and will not heal any surviving lesser-wolves
The Common Build/Playstyle: With  toggled on, activating/deactivating  will allow you to transition from a racing direwolf to a sprinting frame with ravens hovering around you. Use  to mark enemies and kill the marks to feed or alter your lycan form. Then  to morph back, hold- to summon your pack and activate  for a ruthless hunt.
These are some mockups I made showcasing the exalted-form, upgrade and stance: