With the identical hairstyle, fancy suit, nearly identical characterization even being a villain protagonist at one point, demonic form…it’s clear that Kazuya was inspired by Demitri from Darkstalkers. It’s not a coincidence as the first Darkstalkers game and Tekken 1 were released in the same year(1994) with the former releasing a few months earlier. Kazuya is essentially a tribute to Demitri.
Interestingly enough, Tekken would later give tribute to another Darkstalker Morrigan in the form of Eliza. You could make the argument that Lucky Chloe is a tribute to Felicia with the cat aesthetic, dancing fighting style, and being an idol star.