On alchemy (or alchemy+sword) build:
Swallow (+2 vit regen, no side effects)
Rook (+17% dmg, no side effects)
Wolf (+27% incineration/bleeding/poisoning, no side effects)
Golden Oriole (+47 resistance to incineration/bleeding/poisoning, no side effects)
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it fills up whole toxicity bar but you still can drink it... add some oils and alchemy adrenaline buff and whoa ;)
plus with impregnation and few greater crt effects mutagens (+6% each) almost all trash opponents die in fires while bleeding from poisoned wounds, lol
On dragon fight:
Virga (+305% resistances, +32% armor, -1 (one! roflmao) % critical effects)
Rook (+17% dmg, no side effects)
Gadwall (+3 or +4 vit regen, -6% dmg) - i think in next playthrough i'll go with swallow instead... I found that I didn't really need that regen.
All with taster lv1 and catalisis lv2