Councilor Vay Hek

Councilor Vay Hek is the hidden boss located on a secret base on Earth. He is the most political Grineer figure players meet, marked by the Lotus for extermination for upsetting the balance in the system by killing several political opponents. Paranoid for being targeted, Vay Hek now hides in a secret location in which players must extract Beacons found from Prosecutors on Ceres Grineer Shipyard in order to find him. Vay Hek is also heavily modified with Grineer alterations, with little flesh left noticeable while he rides in his giant Terra Frame machine. After defeating him and completing the mission, players will receive a blueprint for either a Hydroid Helmet, Hydroid Chassis or Hydroid Systems. Upon death, Councilor Vay Hek has a chance of dropping Neurodes, Orokin Cell and Argon Crystals.

Mission Access
In order to assassinate Vay Hek, players are required to create a Vay Hek Frequency Triangulator using Beacons found from Prosecutors on Ceres Grineer Shipyard tileset, as well as a blueprint purchased from the Market. Upon using the triangulator, the squad will be taken to a Grineer Forest on Earth where they can face Vay Hek.

Appearance
Like General Sargas Ruk, Vay Hek has undergone extensive body modifications. He appears as a head attached to a robotic suit which all limbs are entirely replaced with mechanical components. It also has a visor to protect Vay Hek's face when activated. In the suit, Vay Hek has the ability to fly or attach himself to a landbound Terra Frame. The Terra Frame gives Vay Hek the ability to use his shotgun, the Hek, and deploy propaganda and orbital strike drones.

Arsenal
Councilor Vay Hek will meet the players after they walk a certain distance into the Grineer forest, laugh, and then fly away. The players have to chase him across the map and progress through multiple phases. Like General Sargas Ruk, he has armor impervious to damage except his face. Each phase involves damaging Vay Hek's face when his mask opens occasionally until he is forced to fly away. At low health during the 4th phase, the final phase begins and Vay Hek flies into his Terra Frame, able to be damaged without needing to aim at a weak spot, but offensively more powerful. When the Terra Frame's health is low, Vay Hek will eject himself out and fly away, and Terra Frame will explode, dropping the loot. Unlike other bosses, this makes him the only boss in an Assassination mission to not visibly die, which helps the idea of re-doing the boss lore wise.

Drone Form=

Machine Guns
Vay Hek has two mounted heavy machine guns on his back, which are surprisingly accurate even at long range. They will fire slowly and begin to spool up, similar to a Gorgon. Fortunately, the guns deal a fairly minimal amount of damage, and can easily be avoided by taking cover behind trees, boxes, etc.

Troop Summon
Randomly throughout the battle, a squadron of four Grineer units will be teleported into battle to aid Vay Hek. These units include: Lancers, Butchers, Troopers, Seekers, and Hellions. While Lancers, Butchers, and Troopers may not be much of a threat, Seekers and Hellions can prove a deadly force when the Tenno are too focused on Vay Hek.

Propaganda Broadcast
Vay Hek opens his mask and begins to broadcast to all local Grineer and Tenno in the area. Nearby Grineer will have boosted defenses and damage, while nearby Tenno will have their shielding reduced to half. As Vay Hek's mask is open, this is the only chance Tenno have to damage him and silence his broadcast. Grineer and Tenno who are affected will have an orange aura around them.

Disrupter Shock
From the second phase on, Vay Hek can target a single nearby Tenno and shock him with a burst of red electricity from his hands. An effect similar to being hit by a Ancient Disrupter will distort the screen, while energy and shielding will be drained. The bolt moves very quickly, and can be very difficult to avoid without fast moving tactics.

Disruption Wave
Vay Hek will begin using this on the third phase. Unlike Disrupter Shock, which targets a single Tenno, Vay Hek will release a fast moving wave of red electricity that travels across the floor. Any Tenno caught in the wave will be drained of shielding and energy and have their HUDs distorted. Like the Disrupter Shock, it can be hard to avoid the wave without careful planning.

Health Drain
When below maximum health, Vay Hek will float near a Grineer unit and begin to sap him of his health. If the Grineer is killed by Vay Hek, he will restore a portion of his health. This can be avoided by dispatching the affected Grineer before Vay Hek can.


 * -|Terra Frame=

Hek Cannon
Vay Hek launches a tracking missile that can deal a significant amount of Blast damage, and can cause knockdowns frequently. Unprepared Tenno can be easily defeated, as the explosions have a wide radius and track moving Tenno. Unlike the Bombard missiles, which follow a Tenno directly, Hek's missiles will predict where a Tenno is running towards, making it difficult to avoid.

Hek Barrage
When low on health, Vay Hek will instead launch 4-5 missiles simultaneously, which is almost guaranteed to cause heavy damage to any Tenno with the radius of the explosions.

Drone Launch
Randomly, Vay Hek will launch 1-4 Drones from his left arm cannon. The number of Drones is dependent on how many Tenno are currently fighting Vay Hek. Drones will float around the area, mostly following the Tenno or staying near Grineer troops. The Drones have two variants, a blue Propaganda Drone or a more deadly red Orbital Strike Drone. Both drones have a small amount of health and can easily be destroyed, dropping ammo, health orbs, or energy orbs. Propaganda Drone A blue drone a floats around empowering nearby Grineer units while reducing nearby Tenno's shields. They do not deal any kind of damage, but can still boost the power of the Grineer backup and Vay Hek himself.

Orbital Strike Drone A dangerous red drone that chases after the Tenno. When a Drone is close enough, it will lock-on to the last location of a Tenno and begin to call in an orbital strike. If the Drone is not destroyed before the lock-on is finished, the orbital strike will fire, creating a massive explosion that deals massive damage to any Tenno within the radius.

Shockwave
If any Tenno wanders too close to Vay Hek, he will jump up and slam the ground, causing a slow, but wide shockwave similar to a Shockwave MOA. While the damage is negligible, a knockdown can leave a Tenno open for Grineer fire or Vay Hek's Charge.

Charge
Used when a Tenno is a medium distance away, Vay Hek will charge up and ram the Tenno, dealing a bit of damage and knocking them back a fair distance, usually into the pit in the center of the area.

Strategy
Vay Hek's protection consists mainly of Ferrite Armor, meaning that weapons with high  and/or is effective to an extent. However, Vay Hek and his Terra Frame possesses a large amount of pure hit points that have no resistances or vulnerabilities against any damage type, making him a difficult damage sponge. Thus it's recommended to use your best weapon with overall high damage to defeat him. This also makes Vay Hek difficult to defeat solo, and thus it's preferable to run this mission with a well-equipped squad.

It is of critical importance to kill the reinforcements (lancers, troopers etc.) on the floor in the last boss area, Doing so will prevent Vay Hek from regenerating his health and will make the fight much easier for the whole party. This is especially true if the party you are with, has a low average of damage per second.

It is also advised to bring Team Ammo Restores if the fight is going to be long because Vay Hek in Terra Frame form has quite a lot of health and people with automatic weapons will run out of ammo pretty quickly.

Utilizing Warframe Abilities
Nova's Molecular Prime will slow Vay Hek, making it easier to shoot his face when he is broadcasting and amplifying damage.

Rhino's Rhino Stomp will stun Vay Hek, making it possible to land lots of hits to his face. His Iron Skin also allows him to negate Vay Hek's disruption abilities. (May not work anymore.)

Mobile frames such as Ash, Loki and Zephyr allow you to position yourself in front of Vay Hek's face in case he turns away from you, allowing you to attack him more easily.

Bringing a Mag (with a few team energy restores) into the assassination can help finish Vay Hek off in his final phase when he combines with his terra frame by using Bullet Attractor. This will redirect all shots near Vay Hek, right to him making it possible to hit him while running around avoiding damage, thus making him significantly easier to beat.

Using The Environment
The final boss arena in which Vay Hek appears is a large open area with a deep lagoon in the middle. A short tunnel directly in front of the area's entry point can provide cover against Vay Hek's attacks in an emergency, and act as a safe area to regenerate shields.

Several objects in the arena, from large fans to high-pressure steam vents - can be interacted with to create powerful wind flows that can propel a Warframe up and forward, allowing a Tenno to traverse the entire arena quickly. This can be useful when catching up to Vay Hek's highly mobile Terra Frame that tend to hop quickly from place to place, and they can also serve to get Warframes away from explosive AoE attacks.

The lagoon at the middle of the arena can pose a significant impediment to Warframe mobility when trying to escape Vay Hek's AoE attacks. To mitigate this, there is a tram hanging from the top of the arena with explosive barrels attached to it. Said barrels can be destroyed to drop the tram into the lagoon, creating a bridge that allows for better movement between each side of the lagoon.

Trivia
If the Grustrag Three are fully scanned, it is revealed that each of them was worked upon by a "Doctor Tengus" who was authorized by Hek himself. Little is known about him, but it is made very clear that he is a prodigy in the field of cybernetics, indicating that he may have had something to do with Hek's mechanical rebirth.
 * Councilor Vay Hek was the person responsible for both The Cicero Crisis and Project Tethra.
 * Councilor Vay Hek was the fifth boss & fourth Grineer boss in the game to receive a complete rework, following Lieutenant Lech Kril, Captain Vor, & General Sargas Ruk.
 * Vay Hek was originally targeted for assassination by Lotus as he is a corrupt diplomat who has assassinated multiple political opponents and is a hindrance to the stability of the system.
 * The new Hek appears to have run from the Tenno in a paranoid panic, leaving him vulnerable if he could be tracked down. This becomes the new reason for Hek to be targeted after Update 13.
 * Prior to his rework, his shotgun was, fittingly, the Hek.
 * His rework appears to have a much larger version of the shotgun mounted on the right arm.
 * Vay Hek's pre-rework quotes had some grammar issues.
 * He can be seen, in his new form, in audio messages during The Cicero Crisis. His appearance suggests he underwent vast body modifications similar to General Sargas Ruk or acquired a battle suit of similar nature.
 * The reworked Councilor Vay Hek seems to be more capable of speaking English than any other Grineer so far. He even has recorded voice clips on all Jungle Regulators spoken in full English when empowering the Grineer units.
 * Councilor Vay Hek is, by far, the character in Warframe who is found the most agitated by the presence of the Lotus, saying that he would personally kill the Lotus once the Tenno has been exterminated from the Solar system, unlike Captain Vor and General Sargas Ruk who simply disregards the Lotus, and instead faces the Tenno as the actual threat.
 * Despite the fact that Councilor Vay Hek is known for political assassinations among public alliances, his pre-rework quotes generate a certain air related to leisure entertainment. These include as gambling, joke-cracking and aggressive commandments, which makes Vay Hek surprisingly similar to many fictional dictators with decent relationships among his peers.
 * Hek has been the source of more Warframe components than any other individual boss, having dropped Trinity, Oberon, and currently Hydroid component blueprints.

Bugs

 * Dying to him may cause you to become unable to move, shoot or use skills.
 * After defeating him, the water in the tunnel may not stop, making it impossible to leave the arena for extraction.
 * After defeating him, he flies off, leaving a zero health Terra Frame that continues to attack and is impossible to kill.