How?
Alchemy build.
Very long, nerdy post ahead.
Get a Clearance Potion, get all your Skill Points back. Put them in Alchemy as follows:
5/5 Heightened Tolerance (Increases potion overdose threshold from 75% to 100%, potion duration time +25%)
5/5 Refreshment (Each potion dose imbibed heals 25% of maximum Vitality, potion duration time +25%)
5/5 Poisoned Blades (Oil applied to blades gives a 15% chance of poisoning the target on each hit, potion duration time +25%)
5/5 Protective Coating (Adds 25% protection against attacks from the monster type the oil targets, potion duration time +25%)
3/3 Fixative (Blade oils do not wear off, potion duration time +15%)
5/5 Pyrotechnics (All bombs, even those that do not usually inflict damage, now deal +150 damage in addition to their normal effects,
potion duration time: +25%)
5/5 Efficiency (Increases the maximum number of bombs in each slot by 5, potion duration time +25%)
5/5 Cluster Bombs (Upon detonation bombs separate into 6 explosive fragments, potion duration time +25%)
3/3 Acquired Tolerance (Every known level 1, 2, or 3 alchemy formula increases maximum toxicity by 1, potion duration time +15%)
5/5 Tissue Transmutation (When consumed, mutagen decoction increases maximum Vitality by 1000 for the decoction's effective duration)
5/5 Synergy (Increases bonus for mutagen placed in mutagen slot by 50%, potion duration time +25%)
5/5 Killing Spree (If Toxicity is above 0, each opponent killed increases critical chance by 50%, potion duration time +25%)
Put Greater Green Mutagens in the slots. Each will give you +900 Vitality due to
Synergy.
Get medium armor, preferably the Manticore set because it's
for this. Put a single point in General:
1/1 Griffin School Techniques (Each piece of medium armor increase Sign intensity by 5% and Stamina regeneration by 5%)
Also with the new "Blood And Wine" mutations get
Euphoria (Each point of Toxicity increases damage dealt by swords and Sign intensity by 0.75%, to a max of 221.25%)
Now you can use as many potions and decoctions as you want. Matter of fact, the higher your Toxicity, which would normally be bad....the stronger you are due to stuff like
Killing Spree and
Euphoria.
I usually use
Katakan Decoction (+5% critical hit chance),
Superior Full Moon (increases maximum Vitality),
Troll Decoction (Regenerates Vitality during and outside of combat),
Superior Maribor Forest (Accelerates the generation of Adrenaline Points, grants 1 Adrenaline Point upon consumption),
Grave Hag Decoction (Each foe slain accelerates Vitality regeneration for the duration of the battle),
Superior Tawny Oil (Accelerates Stamina regeneration), and
Superior Golden Oriole (Poisons now heal instead of doing damage).
With this set up you'll have 18 bombs (20 if you have the vineyard set up in "Blood And Wine") that break into 6 pieces each time you use one, +200% damage to your attacks from
Euphoria and your Toxicity being around 95%, and about 80% chance to critical hit (which also applies to your bombs if you use the Manticore set) due to
Killing Spree.
Any damage you take gets negated by
Troll Decoction and
Grave Hag Decoction. And if the enemy uses poison (and most do) they'll actually
heal you due to
Superior Golden Oriole.
It's the craziest shyt ever.
Fred.
they hit me with the reinforcememts to because I only got to their signal fire after killing like 80% of those fukkers, I don't think I could've prevented that with the direction I approached them. Luckily they were no match for superior hanged mans venom, superior dancing star and Qen
then i see the dogs coming and was like 
cake walk..started going down the stairs and then 8 more dudes popped up 
