Hardcore mode game skulls

Similar to the halo franchise, when creating a hardcore world it would be cool to be able to add "skulls" in order to make the game harder. A few examples could be "Half-Hearted" where the player spawns with only 5 hearts, "Heartless" where the player only has half a heart, "Black eye" where the player will only regenerate half a heart by attacking mobs if already on full hunger, and so many more could be implemented. This could not only make it more fun (and challenging) for new hardcore players, but could also open up a variety of new categories for the speedrunning community.