Super Dungeon Tactics

For this you will need to replay a story mission and kill your character as that character is introduced into the storyline. This is only possible with 2 characters. I would advise doing this with last person you get

on Monastery Mystery since it is fairly short. Much shorter than the kobold warrior guys mission.

Tips: play on casual and stick to either the left, right, or center. Do not branch out as it causes more enemies to spawn.
You must get the killing blow with the same character.