Blood Codes are the physical manifestation of the power held by an individual Revenant in Code Vein II . It forms the foundation for build customization, determining the user's fighting style, favored weapons, and applicable formae. Since they can be swapped out like equipment, they allow you to change your fighting style at any time by altering your base stats, eliminating the need to reallocate parameters or retrain a character. Furthermore, each Blood Codes possess unique effects known as Traits.

Attributes & Burden
The abilities that fluctuate based on the equipped Blood Code influence the Attack power of weapons and formae, as well as HP and Stamina. When equipping Weapons, Jails, and Defensive Formae, Burden is applied to respective abilities. The state of this Burden can result in changes to your character's actions and/or grant special bonuses.