Any Shonnen Ever: This exam has three-five phases, each phase designed to dwindle down the number of remaining applicants. Each of them has a trick. At least one of them will involve you running around a forest for a week hunting down other applicants. And there’ll be a one-on-one fighting tournament at the end. Oh and you might die. Takes 20-40 episodes to complete.
One Punch Man: Standard physical exam to test physical prowess, standard written exam and an interview. Takes half an episode.