The Thaumaturge features strategic turn-based combat that makes you think four steps ahead in order to come out as the winner. Enemy attacks and status effects both cause damage to your health but there are no healing items in the game. So, how do you heal in the Thaumaturge?
How To Heal Yourself In The Thaumaturge

To heal in The Thaumaturge, attack enemies with a Salutor Attack that can restore Health Points or with Wiktor’s Attacks that have Skill Upgrades capable of healing assigned to them. Bloody Rejuvenation is one such Skill that can restore 4 Health Points for every enemy in Suffering State.
Heart Salutor Upyr has attacks like Eerie Intoxication and Not of This World which can restore half the health points you have lost while also dealing damage to the enemy. Word Salutor Veles also has an attack called Slippery Bet that restores 10 Health Points.
This applies to healing in combat. But when you are out of combat, your health automatically goes back to full. So, you don’t need to worry about that. Since you are going to be using Upyr and Veles for most of the game, that will be your primary source of healing in The Thaumaturge.
I found that using an attack like Eerie Intoxication is best when you have lost a decent chunk of health since every subsequent use of this attack or any attack that restores health will restore less each time. So, it’s best to only start using it when your health is near 50% or below.