Invasion Obliteration

For players doing this post Legion:

Greater invasion points can be entered just as a raid portal, you don't have to do three lesser ones first and/or do a specific unlock quest (providing you opened up the Argus questline up till this point on your main)

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• Bosses are on a weekly rotation, finding out rotation and will try to edit / add the rotation as we go (I'm hunting for Sotanathor to complete this ach.)
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• Matron Folnuna was up in the week of 02/02/2019
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• Sotanathor was up in the week of 06/02/2019
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• Inquisitor Meto was up in the week of 13/02/2019
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• Mistress Alluradiel was up in the week of 06/03/2019
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- I've solo'd Matron Folnuna as a i-lvl 387 disc priest easily, the trash / summoned adds don't even see or touch me, the boss herself can't break my shields or damage me. Her mind controlling gasp is the dealbreaker. If everyone (which means you if you're solo-ing) is mind controlled / asleep, she resets to 100% health after a certain time. She does the breath / gasp each time she reaches 100% energy. Not getting hit by the breath for ranged is easy: just step back 2 steps on max casting range. For melee: just stay in her back when she does the gasp.

- Sotanathor not easy to solo, had help from a (random) shadow priest and a warlock, who allowed me to drop off stacks and heal through the ever increasing damage of the stacks. Probably with proper management of the shadowfiend, fade and some running around doable, but difficult. If there'd be a trinket pet or something similar to could take temporary aggro when reaching 2-3 stacks soloable. Without pets / externals, harder.

- Tried soloing Inquisitor Meto, but his tank debuff eventually causes his tank debuff attack to hit you for 800% - 900% of the original damage, without ever dropping off. Disc priests that can't drop aggro on mindbenders and/or trinket summoned guardians or something similar are going to struggle to kill this one. Easier to find two friendly dps/tanks/healers that can taunt/out-aggro you, let them tank switch and kill the boss easily.

You can see which boss is up on the map (go to map, Broken Isles, Argus (in upper right corner)) if you have addons like world quest helper or similar. Mousing over the greater invasion marker on the map pops up the name of the current boss.

Will try to update next week (apologies missed a couple of weeks due to forgetfullness :p )

Couldn't find a fully documented rotation anywhere, so I'll give it a shot for those still missing the achievement:

Week 1: Pit Lord Vilemus
Week 2: Occularus
Week 3: Mistress Alluradel
Week 4: Matron Folnuna

Will keep updating until it loops ^^

For now, based on rabhingm's comment, I would expect the rotation to go as follows:

Folnuna -> Sotanathor -> Meto -> Vilemus -> Occularus -> Alluradel

These bosses are on a weekly rotation. It will take you a minimum of 6 weeks to get this achievement.
You do need to complete Chapter 2 of the Argus Campaign to unlock the Greater Invasion Points. However, it is unlocked Account-wide so nice thing is you only have to do it once.