The Witcher 3 - Lvl 37 vs lvl 50 guards (Death March!)

Alchemy + whirl build. I used 2 mods that affected the gameplay: "Over 9000 - Weight limit mod" and "More Quick Slots and Quick Inventory".
Version: 1.31
Difficulty: Death March! (Level 37 - After base game, during Hearts of Stone, before Blood and Wine)
Build: www.rpg-gaming....
Gear: Mastercrafted Feline Gear (complete set). Enchanted swords with Severance. Armor with 7 greater glyphs of Quen.
Decoctions: Ekimmara, Ekhidna, Water Hag.
Potions: Maribor Forest and Tawny Owl.
Notes:
1. For dialogues, switch one of the skills to Delusion.
2. It looked like I almost died on that fight, but I'm using the Undying skill, which would have completely healed me if my Vitality had reached zero.
3. Best to meditate and fight at night so that Tawny Owl will never expire.
4. With 3 decoctions, my toxicity was 210/247. I could take 1 potion, wait for the toxicity to go down by 3, then take another one. At night this means up to 3 active potions at the same time.
5. I always use Golden Oriole when fighting against enemies that can poison me. Blizzard is probably great on group fights with this build, but I just haven't gotten used to it yet.
6. If the enemy is resistant to poison, or if you don't know which oil to use, you can switch the oil skills to Cat School Techniques and/or Adrenaline Burst.
7. You can use Wraith Decoction instead of Water Hag Decoction against very strong opponents. Most of the other decoctions are useless. Some of them sound like they offer great perks until you figure out the actual numbers involved. For example, Katakan Decoction only increases critical hit chance by 5%. Same thing with some of the skills.
8. This build is great against bosses too, but you have to be careful about when to use whirl.
With that in mind, this is a general purpose build. It works great on any situation throughout the game.