animation two character in game?

It’s called A-B sync animations and assumes the same rigging is being used for all characters and uses root origin (or even root motion) to snap align matching characters (their origin) and scripted animations

A good example of this is the Matinee fight example

So games like Assassin’s Creed or Tomb Raider are heavily scripted where the player really only has control of where the players current origin is located in 3d space