Call of Duty: Black Ops 4

First of all, you need the Alistair's Folly Wonder Weapon and you can get from the mystery box or finding the four different coloured symbols that can be found in the Cemetery, Greenhouse, Forest Terrace and the Mansion areas of the map. Once you have found the four coloured symbols input the code into the safe to get Alistair's Folly for free.

Now that you have the Wonder Weapon you need to start collecting the three different coloured ores around the map. The Red Ore can spawn in the Fireplace in the Master bedroom, Main Hall or the Billiards Room. The Brown Ore can spawn in the Cemetery area near the left entrance by a bush, near the left staircase in the Cemetery area, or it could spawn behind the tree that's on the right of the perk machine.

The Yellow Ore can be found on one of the tables inside the Greenhouse Laboratory area, wither on the left or right side as you walk in or on the table in the far-left corner.

Next is the Silver and the first part for the silver could spawn in the West Hallway along the wall, on top a small red table in the Dining Room, or on the Actual Dining Room table itself. The second Silver part could spawn on a small ledge in the Main Hall, it could spawn on the left table in the Entrance Hall, or it could spawn on the floor in the Billiards Room. The last piece of silver will spawn in the Wining Cellar either underneath a candle on the wall, on the small table or on the wine cabinet shelf.

Now that you have all the necessary parts head to the Wine Cellar to the crafting table to melt the silver, then head to the crafting table in the Library and craft the Silver Bullets and make sure to put the Silver bullets on a good weapon like the Hades or ICR-7.

Then start opening the Pack-a-Punch as normal, then once you open Pack-a-Punch a Werewolf will spawn, YOU HAVE to kill the Werewolf with the weapon that you put the Silver bullets on. Once you kill the Werewolf with Silver bullets, pick up his Chaos Material and head to the Library and melee the bookshelf in the far-left corner of the room with the Shield to pick up the part.

Next head to the Greenhouse Laboratory to craft the Chaos Theory by putting your Chaos Material you got from the Werewolf into the machine and wait for it to finish then pickup the part it gives you then craft the Chaos Theory in the crafting table.

Next step is to head to the Forest area and look for a pile of mushrooms, you then need to kill a Nosferatu with a charged shot of your Chaos Theory when it is on top of the mushroom pile. He will then dig a hole in the ground and hopefully he will dig up the part on the first location, if not head to the two other mushroom pile locations in the forest area and kill another Nosferatu if need be. It’s possible for the Nosferatu to give you the part on the first pile.

Next step is to kill more Nosferatu’s with your Chaos Theory only this time you need to kill them with the Tornado effect, and they will drop Green Bile’s on the floor. You need four or five bile’s, once have enough head to the Cemetery and open the Red Glowing grave and a Crimson Nosferatu will spawn out of it. Kill him to pick up another Chaos Material.

Last step is the lamp step which is in the Cemetery and for this you will want to take note of all the lamps that are currently off, once you have made a note there is a lamp that is glowing orange and it is brighter than all the lamps that are on. You need to shoot the brightest lamp and that lamp you shot will change positions to a lamp position that was not on previously. Shoot the brightest lamp four times, and another Crimson Nosferatu will spawn. You need to shoot him out the sky with your Chaos Theory weapon and he will drop another Crimson Material. If you fail this step wait a minute or two and try again.

Once you have completed this head to the Greenhouse Laboratory and place the two pieces of Chaos Material into the Machine and the achievement will unlock. Pick up both parts the machine gives you and head to the crafting table on the left side of the room to craft Alistair’s Annihilator.

Hope this helped.

If you are still struggling feel free to use these videos I made as a reference.

Call of Duty: Black Ops 4 - Alchemical Opus Achievement Guide

How to craft the Shield

Thanks again!

To unlock this achievement you basically need to upgrade the alistair's polly to the chaos theory and then to the fully upgraded Alistair's Annihilator. To Upgrade the Polly into the chaos theory you first need to craft silver bullets and kill the wolf in the forrest using them, after that you need to head to the library where there is a bookshelf downstairs on the right of the crafting bench that you can melee with your shield opening up a secret room with a blue piece in it that you need to pick up. from there you need to run back to the lab and craft the choas theory. the rest of the guide will be shown down below in the video:
All credit to MrDalekJD