The deadman/ministry is definite INTJ because if you look at his heel turn in 1998, when Paul Bearer joined forces with him again, they decided it was time to unleash the Ministry of Darkness. & he says "Paul gave me time to clear my head". I get the implication that the ministry was their plan all along since his debut, like they were waiting for the right time. But then Undertaker's time as babyface stalled the plan. The biker Undertaker is exactly what the man Mark Calloway is, ISTP. Very impulsive, keeps to himself, unless he's gonna make you famous. Much more focused on the moment & day to day rather than the future. (However, if you remember Vince was the Ministry’s higher power all along. So, it was Vince’s plan all along to screw with people so it was never Undertaker’s plan. So the deadman could be ISTP as well, since he never had a long term vision of how things should be. Undertaker was just part of the Vince’s plan to create the ministry.)
