Tagged time paradox because Doomguy is either Billy Blaze’s son or grandson according to Tom Hall (the wording of his tweet is somewhat ambiguous).
https://www.pcgamesn.com/wolfenstein-ii-the-new-colossus/bj-blazcowicz-doomguy-related

Billy Blaze: "Are ya winning, son?"

Doom Slayer: "DAD! I'm busy killing demons over here!"

That Cyberdemon who cursed BJ bloodline must be sweating hard, if someone ever discovered he created the Doomslayer.