Bump. That invincible dude needs to be boss in future installments, as a fun reminder of who he is to the game. He could be an optional boss, which is what he practically is.
Randal was actually used to test weapons when the game was being made. This is why he outrageously strong for a vandal. None the less, being used for such purposes makes him an integral part of the game and he literally can't be taken from the game. He is part of the coding for the base game