History of Enriching Tonic

Enriching Tonics are consumable potions in Episode: Revenant that modify activity rewards and enemy drops, letting players target-farm loot. The other category is Tonics of different type; see the episode page.

Crafting

Craft them at the Tonic Table beside Eido in the Last City. Recipes unlock tier by tier: crafting a lower tier a set number of times unlocks the next. Ingredients are Reclaimed Vitality plus Enriching Powder (Uncommon), Flake (Rare) or Nugget (Legendary), mostly dropped by Scorn and seasonal activities like Onslaught: Salvation. Default duration is 20 minutes, longer at higher rarity (TheGamer says 20, Dexerto 20/40/60 by rarity).

Shadestalker

The Tonic of Shadestalker Armor is a Rare Enriching Tonic that gives a chance to drop the Shadestalker Suit (per ProGameTalk-style lists; TheGamer's guide did not mention it).