Kela De Thaym

Kela De Thaym is the final boss of Sedna. She can be found on the mission Merrow. She has a possibility of dropping one of the following on death: Saryn Helmet, Saryn Chassis or Saryn Systems blueprints.

Appearance and Abilities
Kela De Thaym appears as a female Grineer with brown armor and a Bombard rocket launcher. Her main attack consists of launching high damaging rockets capable of doing 180 damage per rocket.

Aside from her rocket launcher, she also has the ability to throw two kinds of grenades, a normal explosive one and a smoke bomb variety. She also has the ability to deploy Rollers.

Unlike other bosses, her shield does not automatically recharge. Instead, every time her health is taken down by one-third, she will use a stomp attack that creates a knockdown shockwave around her as well as instantly recharge all of her shields. She also appears to have very high armor.

Kela De Thaym, like other bosses, has unique taunts. Here is a list of them:
 * The sisters... They will reward me well... When I present your head to them...
 * You have forced my hand (player name)... Know that it was Kela De Thaym who ended your existence...
 * I know your name, (player name)... There is little you can hide from me... Run... While you can...
 * Come (player name)... Your end awaits you...
 * First...I will kill you, (player name)...Then...I shall eradicate every last member of (clan name)!
 * The Tenno lives... This interests me... I must learn more...
 * This Tenno... It continues to mock me with its insolence...
 * Tenno, in my domain... No matter... They shan't survive long...
 * Be warned... I will not abide your intrusion, Tenno...

Strategy
While her rockets can be avoided by continuous movement, what makes her dangerous are the Rollers that she can deploy. Three Rollers at once are quite capable of chain-stunning the player and disallowing retaliation, so whenever Kela deploys one, try to kill it as quickly as possible.

Ledge Sniping: A good location for fighting against Kela is on the high ledges on one end of the boss arena. With the height and distance advantage, it is much easier to sidestep the rockets as well as making her grenades irrelevant. The best part however lies in the fact that Rollers can easily get stuck on terrain while trying to make their way up the stairs to you. Even if the odd one does, it's easy to make the Roller jump/roll off the ledge while attacking. This makes it much easier to duel Kela in peace. However, be careful not to be nudged off the ledge by a Roller in the middle of the fight.

Pipes Sniping: Another good location is up on the white pipes on the central stage. The pipes are long enough for the player to strafe left and right to dodge rockets, and is also connected to the two black boxes for even more space. Rollers will generally be unable to reach you while on the pipes, though one may occasionally manage to bounce up and hit you. Be careful not to fall off the stage.

If you do decide to fight her up close, which is not recommended for solo attempts, just remember to keep moving. Try to have one person focus on drawing fire from her while the others attack from behind. If possible, also have a second person focus on destroying Rollers as they appear so that the others can shoot in peace. Keep an eye on her health so you know when she'll use the shockwave attack.

Decoy Trolling: Using either Loki's decoy or Saryn's moult is a great way to draw Kela's fire and distract the rollers. It is recommended that if she is atop the platform you put the decoy behind the railings and out of the reach of the rollers. Several places work for this such as, under the staircases on either side of the platform, atop the pipes near the water or simply using moult in midair a few feet out from the railing. With the decoy in place Kela will focus her attention on it firing rockets and throwing grenades that are sometimes stopped by the railing, or breaking her AI entirely (she'll just stare at it). At the same time the rollers are thrawted because they can't reach the decoy. Thus you're free to attack her without fear of retaliation. As a couple final notes watch her health for the afformentioned shockwave attack and remember that the decoy will have to be restored periodically.

The best equipment for the fight would be a primary with high fire rate such as the Gorgon for dealing with Rollers, a precision secondary such as the Lex for sniping Kela from the ledge, and a Warframe with an AoE attack, as a desperation move for if you do end up being swarmed by several dozen Rollers. If using the Pipes Sniping tactic, a Paris could be a good idea as it bypasses Kela's armor and deals very significant damage to her, and she doesn't move much while in battle, making her an easy target.

Trivia

 * According to Lotus, Kela has a great influence in the Grineer Council. Her assassination would create a power vacuum in the Council and return stability to the system.
 * According to Lotus, all female Grineers undergo combat training, with Kela being one of the most battle-hungry, having extended her term for a decade before returning to the Council court.
 * According to Lotus, Kela is a product of the Sisters, built specifically for combat, with most of her body replaced with combat augmentations.
 * She is the only boss along with Nef Anyo to not have an opening cinematic. (As of Update 7.9.)
 * Aside from the Jackal, she is the only boss to not have an auto-regenerating shield, and instead only regenerates when her health drops to a certain point.
 * Kela appears to be some sort of cyborg, as shown by her unusual speaking patterns.
 * Kela gives the same amount of XP as a normal Grineer Heavy Unit.
 * While fighting her, if she begins to taunt you, her icon has the eye piece on the right side while she has it on the left side.
 * Prior to Update 7.11, Kela had no limit to how many Rollers she can have actively deployed, creating the potential of a sea of Rollers easily overwhelming and stunlocking players.
 * Prior to Update 8, her picture is also used for Kril's taunts due to a glitch.