In Code Vein you’ve got a Blood Veil. It’s the armor that your character wears. Depending on the type of Blood Veil that you have equipped, your character has unique attacks that it can do as drain attacks. There are a couple of ways that you can use the Blood Veil to use drain attacks and gain Ichor in the process.
The Blood Veil and its drain attacks are what are used when you hit a successful parry on an opponent. You can find more on how to Parry in Code Vein.
You can also use your Blood Veil when doing charge attacks. These can be done by holding the A Button on the Xbox Controller (X button PS4 or the Control and LMB on PC).
You’ll also use the Blood Veil when you do Backstab attacks. Simply walk-up behind an enemy and press the light attack button. If successful you’ll get a drain attack using the Blood Veil.
Depending on the Drain Attack Type, and the Blood Veil, you will get different animations from the characters.