General Sargas Ruk

General Sargas Ruk is the final boss of the Saturn system. He can be found on the mission Tethys. After defeating him and finishing the mission, you receive either Ember Helmet, Ember Chassis or Ember Systems blueprint. Has a chance to drop an Orokin Cell upon death.

Appearance and Abilities
Sargas Ruk appears as a beefy, heavily armored orange cyborg cyclops. He makes extensive use of cybernetic augmentations. Notably, his right arm is replaced with a flamethrower-type weapon.

Defensively, his armor makes him immune to any damage, save for several weak spots which are revealed as the fight progresses.

Offensively, his cannon provides him with several special abilities along with the regular flamethrower attack, which he uses at medium range. When in melee range, he can bash the player with his cannon.
 * Fire Bombs. Fireballs fired from his arm cannon, they have a moderate AOE and knock the victim down if they are caught in the explosion. The projectile is homing but is easy to avoid thanks to it's low angular velocity.
 * "Hellstorm". Smashing his arm cannon into the ground, he can envelop himself in an ever expanding dome of blazing fire. Any Tenno caught in it will be knocked down, pushed away, and be dealt a significant amount of damage (approx. 400). Has an enormous range, capable of taking up a quarter of the arena. Starts being used from Phase 2.
 * Inferno. The cast motion is similar to that of Hellstorm, but instead it will cause pillars of flame to erupt from the ground near the Tenno, dealing heavy fire damage. Starts being used from Phase 3.

Taunts
General Sargas Ruk, like other bosses, has unique taunts. Here is a list of them:
 * "What flesh is within that (warframe)? I will crush it. I will fill my lungs with your death."
 * "Forget The Lotus. Grineer are your masters. Submit for mercy."
 * "Too easy. I expected more. I deserve a challenge."
 * "Are you just mercenaries? Fighting for scraps? Where is this so-called Tenno honor?"
 * "You think you are guardians? Grineer rule supreme. Grineer protect all."
 * "You Tenno. You fight for treasure. You are just another Corpus machine to me."

Strategy
The battle is divided into 3 phases. Each phase begins when he loses 1/3 of his health. Generally, do not get close up to him and do not waste ammo as he can only be damaged by shooting his weak spots, each being exposed for a short duration after his attacks.

Due to his very high armoring, it is advisable to bring a weapon with high Puncture damage capability such as the Vectis, Lex or Hek in this fight.

Phase 1

During the first phase, Ruk will use his cannon as a flamethrower (like Ignis) as main means of attack. And if the target is out of its reach, it will occasionally launch homing napalms, hybrid of both Napalm's and Bombard's weapon.

His weak spot is located in the generator mounted on his left shoulder. The generator is usually exposed for short amounts of time after his attacks, often after a reload. Keep your eye on him and shoot at the generator when it is exposed.

Phase 2

Once his shoulder generator is destroyed, Ruk will add the Hellstorm to his arsenal. Since it is hard and pointless to dodge his Hellstorm (due to it's speed and it's very large AoE), it is advisable to tank it with your shields instead. You can also attempt to hide behind cover, just make sure it's big enough to shield your entire body. Despite its massive range, if you've kept your distance on Ruk throughout the fight, you should have enough time to escape the flame.

The second weak spot is located within his chest. The chest generator opens for a few seconds after he uses Hellstorm, presumably to cool down. Whenever a Hellstorm is used, simply run backwards while keeping your sights on him, and blast away once the blinding fire dissipates. Aside from that, it's the same strategy as in Phase 1.

Phase 3

Once the chest generator has been destroyed, Ruk will start using Inferno. The key to dodging the pillars is mobility. Make sure to keep an eye on where you're going, and make sure you don't run right into an erupting pillar.

The final generator is located on his back, and is revealed during and after either Hellstorm or Volcanic Pillars. For groups, having one or two Tenno be situated behind Ruk at all times will allow quick retaliation after a Hellstorm. For solo however, due to the range of Hellstorm, it'll be rather difficult to run around and behind Ruk before he turns around, so Volcanic Pillars is your best bet.

However, when he uses his most dangerous ability -- Inferno is when he is as his most vulnerable moment. The generator on his back will always be open, flank your way to his back and  The reason for running far behind him and then closing the distance instead of running close behind him and backing away is because a Pillar will probably erupt in front of you and block your vision if you do the latter.

Combine this with the strategies in the first two phases until Ruk is extinguished and victory is yours!

Trivia

 * Sargas Ruk is the third boss to receive a complete overhaul, after Captain Vor and Lieutenant Lech Kril.
 * Pre-Update 9, Sargas Ruk was generally the second Grineer boss that players will encounter, after Captain Vor.
 * According to the mission briefing, Sargas Ruk had been raiding and annexing Tenno-controlled dig sites in the region, which is the main reason that led to him being targeted for assassination. He is also the main Artifact Hunter of the Grineer faction.
 * It is said that Ruk has a deep hatred for any Non-Grineer. He also considers flesh as a flaw, and implanted many body modifications into himself as a result of his pursuit for "Grineer perfection".
 * As of Update 8, Ruk has been moved from the Asteroid Base to the Galleon. Ironic, as Ruk is the only Grineer boss who really belonged in an Asteroid base due to his background as an artifact hunter invading Tenno-controlled dig sites.
 * Very rarely, Ruk will "double-drop" mods, although this is purely a visual glitch and the second mod is actually a resource. This has only been observed to happen with Orokin Cells.
 * Interestingly, during the Zanuka Project spoilers, Ruk is the one who puts forth the ultimatum to Alad V, even though Ruk is not generally associated with diplomatic encounters, as he is the main artifact hunter for the Grineer.
 * During The Gradivus Dilemma Ruk appears in his new form during the loading screen of contested levels and his new face is depicted during his dialogue.
 * Ruk speaks English to the player in his dialogue in the Gradivus Dilemma and when taunting the player on Tethys, albeit with apparent difficulty. It is unclear whether this is due to trouble with speaking the language or Grineer genetic deficiencies.
 * He is also the first boss to have unique voice lines for each taunt and have said lines match the subtitles.
 * In spite of his apparent hatred for non-Grineer, he still welcomes Tenno support, albeit with a somewhat condescending attitude.
 * If sided with the Corpus, Sargas Ruk will have the tendency to taunt against Alad V and the player, referring that the Tennos are made of metal. This is a contrary speculation of the Technocyte construction of the Warframe armor as the armor is said to be organic and the idea of Tenno might not actually be human themselves.
 * This might bring to mind about relationship of the Orokin and the Warframe during the Old War.
 * He has created a forum account on the warframe forums to argue with AladV: SargasRuk
 * In-game, his "cyclops eye" and other lights on his armor glow blue, despite being orange by default (as seen in lobby screens and on his avatar).

Media
Post-Overhaul