This is taken from the Powerpyx Roadmap and is from what i believe the fastest and hassle free way to obtain this achievement.
https://www.powerpyx.com/remnant-2-trophy-guide-roadmap/#gho...managed to snag the achievement in a matter of minutes.
The only downside is that you wont be getting any extra Corrupted Lumenite Crystals.
1.Either play offline or be the host of a co-op session.
This step is here because until a patch arrives this achievement can reset when joining someone else's game, or not even give you any progression.
2.Reroll N’Erud until your starting area is Seeker’s Rest.
3.Proceed through the level until you either reach the main area The Eon Vault, Phantom Wasteland, or Timeless Horizon.
4.Now proceed to any white-marker gate and enter it.
5.If you’re lucky, you’ll get Tower of the Unseen. If not, leave and try with any other white-marker gate. If none of the white-marker gates you find in your first main desert-like area lead to the area we need, progress with the main objective until you reach another main desert-like area among the possible three ones. Try again here, but if you don’t find Tower of the Unseen here either, you’ll have to reroll N’Erud.
6.Once you’ve lucked out, continue on until you have to fight against an Aberration boss called E.D. Alpha. This boss spawns smaller flying orbs that are Aberration enemies themselves, too. Simply kill enough of these until you’ve unlocked both trophies.
This is what he looks like. shooting the smaller orbs flying around him counts as killing abberations.