i've thought of a new ruleset for a 1.2 hardcore playthrough:
hardcore mode
no armor
no RoD, mounts, lifeforce or gravitation potions
no recall/mirror can be kept in toolbar, making escaping deadly situations harder
160hp is max
ranger only
lategame bosses will kill your hardcore character in a couple of hits. goal would be to kill the final boss of that version, that being duke fishron.