23 year old Y/n L/n was invited by his friends to go to a comic convention gathering for his 23rd birthday. When he arrived at the convention hall with his friends, he was dressed up as John Constantine from the Arrowverse show of the same name. As his friends(himself included) agree to split up and meet up at a designated location, Y/n was looking at stall after stall until he was drawn to a particular stall that is selling a(seemingly) replica of Dr. Fate's helmet that is being manned by someone dressed as the merchant from Resident Evil. After making the purchase for the replica helm; as Y/n was in the middle of putting on the helmet, he heard the voice of the merchant guy saying something to him, but he couldn't hear what it was as he passed out.... (A/n: I do not own Hazbin Hotel, nor do I own DC Comics, Helluva Boss, or any other things featured in this fanfic. They belong to their respective owners, all I own is the crossover idea!)