A blade in the shadows, master assassin, the actual ninja in a space ninjas game - Ash!

Passive: Slash procs inflicted by Ash's weapons and abilities deal 25% more damage and last 50% longer.
Shuriken - Launches a spinning blade of pain, dealing high damage and impaling enemies to walls.
Smoke Screen - Drops a smoke bomb that stuns enemies and obscures their vision, rendering Ash invisible for a short time.
Teleport - Ash teleports towards the target, bringing him into melee range and making enemies vulnerable to finishers.
Blade Storm - Project fierce shadow clones of Ash upon groups of distant enemies. Join the fray using Teleport.

Acquisition: Main blueprint can be purchased from the Market. Component blueprints are obtained from Venus Proxima (Systems), Neptune Proxima (Neuroptics), and Pluto Proxima (Chassis) Survival, Defense, Exterminate, and Volatile missions.

The rock, puncher supreme, 0% neck slider - Atlas!

Passive: Atlas is immune to Knockdown while in contact with the ground.
Landslide - Bash enemies with an exploding sliding punch, and repeat for a devastating combo. Petrified enemies take extra damage, and drop Rubble when destroyed. Rubble can heal Atlas and bolster his armor.
Tectonics - Summon a rock-wall, activate again to send the rocks crashing towards the enemy.
Petrify - Atlas' hardened gaze will fossilize foes, heal Rumblers, and create Petrified Bulwarks. When shattered, petrified enemies drop healing Rubble for Atlas.
Rumblers - Summon two elemental stone brawlers to the melee. Summoning petrifies enemies in close proximity to Atlas. When finished, Rumblers collapse into a pile of healing Rubble.

Acquisition: Main blueprint is awarded after completing The Jordas Precept Quest. Component blueprints can be obtained from defeating the Jordas Golem on Jordas Golem Assassinate, Eris.

The necromancer, master of the dark arts, the original loot frame - Nekros!

Passive: Nekros and his Companions regenerates 5 Health when an enemy dies within 10 meters of him.
Soul Punch - A blow so powerful, it turns the enemy's very soul into a deadly projectile, damaging all in its path.
Terrify - Casts fear into the hearts of nearby enemies, causing them to run away in terror.
Desecrate - Forces fallen enemies around you to drop additional loot.
Shadows of the Dead - Summons shadow versions of vanquished enemies to fight alongside you for a short period of time.

Acquisition: Main blueprint can be purchased from the Market. Component blueprints can be obtained from defeating Lephantis on Magnacidium, Deimos.

The huntress and her loyal companion, mistress of chains, Whipclaw goes brrrr - Khora!

Passive: Khora's ferocious Kavat, Venari, fights alongside her with steadfast zeal. While Venari is alive, Khora passively gains a 15% movement speed boost. If Venari is killed, she will respawn beside Khora after 45 seconds, or instantly if summoned via the third ability for an energy cost.
Whipclaw - Send enemies reeling with a deafening whipcrack.
Ensnare - Bind a hapless target in living metal, entangling others who stray too close. Whipclaw will refresh the trap allowing it to capture more enemies.
Venari - Command Venari to focus on a target. Hold to cycle between Attack, Protect, and Heal postures. If Venari is killed, use this ability to revive her instantly.
Strangledome - Weave a dome of living chain that ensnares and strangles any enemy within, and any foolish enough to approach. Foes outside the trap will try to hasten their comrade's deaths by shooting them. Crack Whipclaw on the dome to further damage any trapped enemies.

Acquisition: Main and component blueprints are acquired from standard Sanctuary Onslaught.

The immovable force, an ironclad warrior, wearer of the mightiest codpiece - Rhino!

Passive: If Rhino falls far enough to incur a Hard Landing, the ground impact will discharge a shockwave that deals Impact damage and Knockdown in a 6 meter area of effect.
Rhino Charge - Rhino charges towards a target, clobbering any in his path and goring his victim.
Iron Skin - Rhino hardens his skin, insulating himself from all damage.
Roar - Grants all nearby Warframes increased damage for a short duration.
Rhino Stomp - Rhino stomps with force sufficient to disrupt time, tumbling enemies around him in stasis.

Acquisition: Main blueprint can be purchased from the Market. Component blueprints are obtained from defeating Jackal on Fossa, Venus.

The elemental alchemist, Orokin executioner, serpent whisperer - Lavos!

Passive: Lavos cleanses all active negative Status Effects and gains status immunity for 10 seconds upon collecting an Energy or Universal Orb. Picking up an Energy or Universal Orb has a cooldown of 5 seconds.
Ophidian Bite - Lash out with a toxic serpentine strike, consuming the target to heal Lavos.
Vial Rush - Dash forward, crashing through enemies and leaving an icy trail of broken vials.
Transmutation Probe - Launch a probe that converts Health and Energy Orbs into Universal Orbs that provide both, and ammo pickups into Universal Ammo Pickups. The probe shocks enemies in close proximity. Each electrocuted foe reduces other ability cooldowns by one second.
Catalyze - Catalyst Probes erupt from Lavos and douse combatants in a fiery gel. Damage is doubled for each element afflicting an enemy.

Acquisition: Main and component blueprints are available from Father with Entrati standing.

Zephyr Prime is up +6.81% with basic Zephyr up +10.50%! I shall claim full credit for causing this change! Glad more people discovered the power of the bird last year.

The vampiric healer, the original support frame, lobster skirt - Trinity!

Passive: Trinity and allies in her Affinity Range gain Lifegiver, which increases their Health equal to 50% (25% in Conclave) of Trinity's total Energy pool.
Well of Life - Create a well of life on an enemy who will absorb Status Effect damage intended for nearby allies. Allies gain additional Health when they attack the target. If allies die, enemies in the well of life die in their stead.
Energy Vampire - Allies will gain energy over time when enemies are marked with Energy Vampire.
Link - Any damage taken while Link is active will be channeled to a nearby enemy.
Blessing - Restore the health and shields of allies within Affinity Range while reducing the damage they take from enemies.

Acquisition: Main blueprint can be purchased from the Market. Component blueprints are obtained from defeating Ambulas on Hades, Pluto.

The psychic, mental manipulator, strongest minion frame - Nyx!

Release date: 2013-01-29

Passive: Nyx gains Thrive in Chaos whenever enemies within Affinity Range are afflicted with Confusion (from Radiation status effect or Mind Control), increasing her primary and secondary weapon Critical Chance by 40% per enemy up to a maximum of 200% from 5 enemies.
Mind Control - Nyx seizes control of a target's mind, compelling them to fight for the Tenno cause. Controlled enemies have increased Radiation Status Chance. When Nyx shoots them, they also have an increased Damage Multiplier.
Psychic Bolts - Nyx unleashes a volley of psychic bolts that track and strike nearby enemies with telekinetic precision. When enemies are slain, additional bolts scatter to new targets. Striking foes weakens their defenses and transfers a portion to Nyx.
Chaos - Nyx releases a devastating psychic pulse, disorienting enemies in a wide radius and forcing them to turn on each other. Confused foes lash out at random factions.
Absorb - Nyx draws in and contains the damage dealt to her and the damage confused enemies deal to each other then converts it into a devastating radial blast. Following the blast, she enters a brief invulnerable state and gains a Weapon Damage boost proportional to the absorbed damage.

Acquisition: Main blueprint can be purchased from the Market. Component blueprints can be obtained from defeating Phorid on assassination missions that appear during an Infested Invasion.

This is a bit of a unique twist on the weekly warframe format, instead of me bringing you the frame, it's time to do the opposite! (this is totally not because I have no ideas for a thread myself, nope!) Doesn't matter if it's an incredibly niche or a very popular warframe, if you have something to say about your favorite (or most hated) frame - this is your chance! Maybe you have a concept for a frame that doesn't exist but you wish it did? This is also the perfect chance to bring it up!

The bird queen, air elemental, most underappreciated frame - Zephyr!

Release date: 2014-02-05

Passive: Striking from the skies above, Zephyr is significantly lighter in comparison to other Warframes, dramatically altering her airborne physics. While airborne, Zephyr’s equipped weapons gain a 150% Critical Chance bonus.
Tail Wind - From the ground, charge and release to launch Zephyr into an airborne hover. From the air, tap to dash forward, or aim down to dive bomb enemies below.
Airburst - Launch a burst of massively dense air. Hold to send enemies flying, tap to pull them toward the burst. Damage increases per enemy hit.
Turbulence - Creates a wind shield around Zephyr, redirecting all incoming projectiles.
Tornado - Create deadly tornadoes that seek out and engulf enemies. Tornadoes deal the elemental damage type they absorb the most. Shoot enemies engulfed in Tornadoes to do additional damage.

Acquisition: Zephyr’s blueprints can be researched from the Tenno Lab in the dojo.