I think the game and community would benefit a lot from adding even just minor support for this kind of gameplay. Even just adding an NPC that grants a player that hasn't died yet a title or something that they can lose on death - similar to what WoW classic hardcore did with the mysterious stranger NPC that grants any player that hasn't died a buff that reads "This player has never known death". This very small update would be non-intrusive and allow players to challenge themselves with a deathless character run without the commitment of selecting a hardcore option that prevents your character from spawning after death like in Diablo 2. If you die you lose the title or ability to obtain the title if you died before talking to the NPC.
Hardcore doesn't feel like a real thing to me in maplestory. Between auto-pot and zero cooldown on potions, the only reasons you should ever die are either completely out of your control (lag spike, indoor sack mob ambush at low level), or simply due to negligence/carelessness (running out of potions, setting auto-pot wrong, letting pet go hungry, etc) - contrast with games like WoW or Diablo where there's a considerable skill/strategy element to staying alive. That being said, it would be pretty neat to have an NPC you could visit for stats like number of deaths, and it would probably be simpler to implement than major changes to the character creation process and UI. Although stats would probably only make sense for characters created after the feature was added.
While we respect alternate playstyles like Ironman or Islander or this hardcore/permadeath one they usually rely on honesty within the group. That being said there are no plans to introduce a system to track deaths. Thanks for your feedback!
