Path of Exile

This one is easy, you can use poe.trade to buy divine vessels and then, in some maps in the Atlas, you will find that they have special blue text telling you that the boss of the map has a soul you can enslave.

Then simply put a map and a divine vessel inside the map device and defeat the boss.

Take the vessel from the map device after getting out.

Give the vessel to Sin in town.

Repeat for all maps and the achievement will unlock.

This is easier with currency. Go to poe.trade to buy the maps or /trade 820 to trade high tier maps for others, for those difficult maps you arent able to beat, you can find people offering their clear services but ALWAYS ask for a reference thread in the path of exile forums, there are a lot of scammers out there.

This achievement asks for only completion, not all bonus. So you can do white maps and it will count.

The most expensive maps for this achievement are the unique ones, Perandus Mansion, Vinktar square, Putrid Cloister, they are not diffcult to clear but hard to get.

The Vaal Temple map, can only be bought or corrupted, it doesnt drop. You need to vaal orb a T15 or T16 map for a small chance for the map to morph into Vaal Temple.

You can also join a guild and ask your guildmates for your missing maps and even come together to buy an expensive map so you all get the map credit once you clear.

You need to kill the shaper of worlds to complete the Atlas.
Some maps are very tricky to complete you can hire people to help you complete those maps through /trade 820 or the forums.

There are several ways to improve your chances to get more Essences in your maps.

Unfortunately, the number of essences per frozen enemy is random, you can get from 1 to 5 in any level of maps.

But since Essences dont happen in every map you open, there are ways to better your odds or guarantee you find essences in your maps.

1. The first one is to open the map with a Essence map device mod, depending on the league, you will need to have to a certain favor level or bonus objectives completed but once you unlock this, you can pay a few chaos orbs before opening a map to 100% guarantee you will have at least 2 mobs frozen with essences.
2. You can use sextant mods, buy a sextant by poe.trade but search for the ones that give you increase in Essences.
3. You can allocate "skill points" to the Atlas to increase Essence chance on maps to better your odds.

Oh yeah, if you find one with 4 essences and its not corrupted already, you can use a Remnant of Corruption to maaaybe get a 5 essence.

Abaxoth is the Ultimate Beyond Boss Demon, it has a lot of different attacks and its one tough cookie to kill.

He only appears in maps above level 68 and sometimes when you kill all members of his voidspawn.

To increase your chances, get maps with the Beyond mod or the Bloodline mod (for voidspawns), also.. you could just pour chaos into the map device to choose the beyond mod (you can double beyond with a beyond map using the beyond mod in the device), now a days, there is the map skill tree which you can use to increase your Beyond chances and you can buy the Beyond mod on your map portals befor opening one not to mention sextants.

Another easy way to do this is to play a league that has a challenge to kill Abaxoth, players will often sell the kill for some chaos.

I recommend you check out /trade 820 if a league has Abaxoth as a challenge or ask around in normal trade or global, maybe someone will sell you the kill.

Vaal Oversoul is the final boss of Act 2 located in The Ancient Pyramid. To get this achievement you need to kill him while you have the Fortify buff active. The fortify buff can be acquired in many ways such as skill gems,skill points, weapons etc. The easiest way is to just use the skill gem "Vigilant Strike" as it grants you fortify buff when using.