I was thinking about the ability to revive dead people. Probably within a shortish time window (3 ingame hours or so), will probably be abused by alts but what won't. Welll you could make it have certain requirements (learn a skill or some sort of stat requirement) but alts will have that too.
I think this would make some pvp fights more interesting as well as making people play together in general. Idk revive could heal the target for 10hhp per tick and with some special items or skills it goes a lot faster.
When revived there is a lot of room to indroduce all sorts of wounds. 1 ingame day of coma (you could tp to hearth) althought this would be quite boring gameplay but maybe also solvable if another character heals you in some way
50hhp permanent wound that only lets you use 1 arm slot or move at 1 speed slower than normal - can only be healed by ancient root
you could introduce wheelchairs metal and wood that let you move at normal speed but you need them to move the wound causing this also permanet and can only be healed by ancient root or some magic stuff
-50% int for a stupid long time
idk what else, a lot of possibilities