One of the first big choices you are forced to make in Vampyr shows up in the first hour of the game. Right after you finish the Prologue, Jonathan will be brought to the hospital where he watches a man kill another person. The one surviving is wounded and will ask Jonathan to help heal him before he dies. This presents your first big choice in Vampyr, as the player is able to both save or kill Clay Cox.
While the idea of gaining easy XP is tempting we recommend holding off on killing him for now. Like other NPCs, Clay has a ton of hints and a backstory for the player to uncover. This will increase his XP yield – maximum is a 1,000 – and help you out later in the game. After speaking with Clay you will get the option to Spare or Embrace him. Pick the former and make sure to tell the nurse about fetching him so he doesn’t die. After this happens, Clay will become a permanent resident of the hospital location.
Continue through the story, but make sure to speak with him occasionally to unlock new Hints and eventually a mission. Clay will ask Jonathan to retrieve his knife, which is inconveniently surrounded by angry Skals. We don’t recommend doing this quest until at least Chapter 3 to ensure you have some upgrade abilities and potentially your Ultimate. Follow the white head marker to the location, kill the enemies, and obtain his knife. Bring it back to Clay and he will reward you for your trouble.
After this is done you are free to kill Clay without any real repercussions. Just lead him down to the docks or into the hospital storeroom to kill him. Clay’s death won’t have a dramatic effect on the world since he is considered one of the expendable characters. Plus, he is a terrible person and you shouldn’t feel bad about feeding off him. Just remember, once you choose to feed on Clay he will be gone for good. Unlike other characters, you won’t need to raise your Mesmerize level to kill him. He is stuck at 1 so you can mind control him anytime you wish.
If you finish Clay’s quest and he isn’t at 1,000 experience make sure to he’s not afflicted with any diseases. Any kind of illness will dilute the blood and cause the player to obtain less XP when they bite an NPC. If Clay does have something, just go back to your workshop and craft the disease. You can purchase any needed medical materials from the vendor to the left of the hospital’s main entrance. If Cox has a headache, just use this guide to find the needed formula in Vampyr.