Blue are tanks, red are DPS, green are healers. While tanking the cannons, you're in range to do everything except Rocket Punch (damn you BioWare!). Don't be afraid to blow taunts, since pretty much the only way you will wipe on this fight is cannons targeting non-tanks. Mine are used almost on CD because of the rough aggro gen here. It should be noted that melee DPS with jumps can jump to the cannon and stand on top of it as long as it is not facing them. If the cannon turns towards them they get knocked back down.
Annihilation Droid XRR-3: Once the cannons are vanquished this bruiser will fly down and land in front of you. Jet Charge over to him and start laying on the hurt. Tank him facing the door with the raid behind him.
Overwhelming Swipe - When XRR-3 does this, you will be knocked far back. This is the reason you stand in front of him alone. The other tank should taunt and move to where you were standing when this occurs, giving you time to run back without the raid wiping.
Targeted Missile - Yeah, no clue what this ability is actually called. If you see a target on your character, move away from other raid members because the missile will do pretty strong AoE when it hits you.
Storm Protocol - Don't stand in fire. Red targeting circles appear on the ground. Step about a meter to the left or right and you'll be fine.
Missile Barrage - XRR-3 will crouch down and start channeling. Everyone in the raid should LoS him behind the defeated cannon towers to avoid massive damage. Make sure one healer goes to each tower so everyone can get healed up during this. When it ends the robot will stand back up, signalling you to go back in. When XRR-3 reaches 10% health, he will cast this continually until his demise. Zerg him down. Make sure everyone has their cooldowns up for this phase.
Trash: The big floaty sensor droids are easy. Just pick them up and single target or AoE them down. The black ones do have a knockback so watch your positioning. It is very easy to be knocked to your death and it is a long run back. The sensors and flesh punchers (THWACKTHWACKTHWACK) are ancestral enemies, so if you see a mixed group just wait 10 seconds or so and the sensors should kill the flesh punchers for you. In the fire area, the humongo akk dogs are similarly not a threat. Pick them up and single target or AoE them down. Use Flame Sweep liberally on all these trash pulls. I tank with an Assassin so he is usually the one with most of the mobs on him (damn his AoE aggro!) leaving me little to do.
Gharj: Uggggggg. I feel like this fight is extremely glitchy. Anyway, here is how it SHOULD go. When the fight starts, have the raid run towards where the boss is standing. Meanwhile, you shoot the boss and drag him near the rocks you came in on. This saves A LOT of hassle with trying to position the boss with his back towards the raid. Gharj has a strong cleaving attack so make sure everyone except the tank is behind him.
Leap - AoE damage. Heal through it.
Pulverizing Slam - High damage to the tank.
Frenzy - Gharj will hop up and down like a bunny on crack, dealing massive AoE damage. Everyone in melee besides Gharj's tank should run and stack on the healers until this ends.
Howl of the Akk Dogs - Well, this may not exactly be a casted ability, but Gharj will occasionally summon a pack of low health adds. Have the tank not on Gharj pick them up and just AoE them down.
Knockback - Gharj will sometimes knock your raid back into lava. Just run back to the platform and heal up. The lava doesn't hurt too badly.
Smashing Leap - Gharj will hop up and down, covering the island with lava. Meanwhile, a stepping stone path to another island will emerge from the lava. Hop over there and have the tank stand on the far side of the island from the path. When Gharj jumps to the new island, the tank should pick him up exactly as in the initial pull.
Trash: Leaping manka cats, Batman! Group them up and AoE them down.
Pylons: Split the raid into two groups, with one tank, one healer, and two DPS each. One group goes to the north pylon and the other to the south pylon. The goal here is to use the left and right consoles to turn the wheel, making the middle symbol match the ones on the side. Once both north and south have the correct symbol on the bottom level, the next level is unlocked. When all symbols on both towers are correct the chest in the middle opens and you can proceed.
During this, adds will spawn. Three Rakata spawn at a time around each pylon. These are high damage normal mobs. They have extremely low healths and should be killed quickly. The last mob to spawn should be a proto acklay. These HURT. Pop cooldowns if you are getting hammered by one and feel like your life is threatened. If the tank dies, this can easily wipe the rest of the group. Burn it down as quick as you can.
Infernal Council: The 1v1 room. Have each person in the raid go and stand next to a council member. Tanks should take Juggernauts, healers should take Assassins, and DPS should take Marauders. When the console is activated, the council members will be freed and will drop to the ground. Engage your target in a duel of fate. Note that these are all one on one fights. If you try to heal anyone in the raid, or attack a target that is dueling someone else, you will receive a debuff reducing all healing and damage done by you by 100%. Just beat down your target and wait for everyone else to do the same, then loot the chest.
Soa: The big bad of Eternity Vault. Run out and engage him, turning him away from the raid. For the first few seconds Soa is invulnerable, so simply Jet Charge over to him and save your attacks until the shield goes off.
Weird Blue-Green Puddle - The fire in this phase is bluish and liquid. Don't stand in it.
That's literally the only mechanic in phase one. When Soa's health drops low enough (~75%) he will put up a blue immunity shield. This is your queue to run to the outer ring. In a few seconds the middle two sections of the room will drop out from under you. Go quickly. You want to have everyone meet up where the yellow X is, by the room's entrance. As Soa's tank I prefer to run straight to the outer ring and then walk around to the X as opposed to running straight to the X (I had the floor drop out from under me on my way there before).
Now you are all grouped up in the outer ring. Find the highest up platform and hop down to it. You will see a traffic cone (Ancient Power Source). Break it and then hop to the next lowest platform. Continue all the way down like this, stopping to AoE heal when necessary. Be careful never to dally too long or the platform you are on will drop.
For the tank, phase two is pretty much the same as phase one. There are three mechanics in this phase.
Mind Trap - Soa will summon a mind trap that will suck a raid member into it. That raid member will have to kill an extremely easy normal version of Soa and then wait to be rescued. DPS not in the mind trap should prioritize killing mind traps over hitting Soa.
Ball Lightning - A glowing lightning ball will sometimes appear and randomly aggro onto a raid member. That person should kite the ball away from others. Always avoid being near lightning balls no matter if they aggro on you or not. They do hefty damage when they explode.
Force Cyclone - Soa will sometimes grab a random raid member and fling him around the room. That raid member can take no actions until the cyclone ends and is effectively just CC'd. There isn't a way to free someone trapped in this besides waiting for the effect to end on its own.
Once again, when Soa is damaged enough (~30%) he will put up a blue immunity shield and prepare to drop the floor again. Group your raid on the outer ring and proceed down as before, killing traffic cones and healing on your way. When you hit the ground again, the last phase starts.
In this phase, Soa will keep his immunity shield up and continue using all mechanics from phase two. The tank should grab Soa and just drag him around the room with him. DPS should ignore Soa when his shield is up and instead focus entirely on mind traps. The tank should be keeping an eye on the air above the raid. Periodically, Soa will levitate massive orange-glowing pillars above the floor. The tank's job is to drag Soa under the pillar so that when it hits the ground, it hits only Soa. It WILL hurt if it hits you so do your best to position yourself away from it. When a pillar hits Soa, his immunity shield drops and all the DPS should switch off mind traps and onto him instead. When he recovers and raises his shield again, DPS should get back to mind traps and the tank should resume his search for levitating pillars. Just keep doing these mechanics until you down Soa.
Congratulations! You conquered the Eternity Vault!