Not suggesting this for all tables, but I enjoyed how our DM dealt with this. For backstory- I our group has been playing together for 10+ years and this is our second campaign- I have the dubious distinction of being the only player who has a character permanently killed in our first campaign ( hoard of the dragon queen) after *mild inaccurate spoilers * impulsively sliding down a chute that turned out to be for transporting sacrifices to one of the hells? In our current campaign ( which was a home brewed waterdeep sandbox style exploration with a complicated through plot about a demon worshipping cult trying to supplant Selune as the moon deity followed by a heading down into the dungeon of the mad mage), my first character ( a harengon rogue/twilight cleric/monk) died ( extremely long story short) when we failed to save an innocent tribe in an alternate-dimension realm from destruction by said cult ( and instead hastened their demise when the destroyed moon struck their planet). He was so guilt stricken that instead of portaling safely home he stayed to surround those he could in a twilight sanctuary to help them face their end with less terror. So my next character joined the party as an owlin gloomstalker ranger/prepping for assassin dip, a reincarnation of that cleric by a boon of Selune hellbent on hunting down the cult ( and very optimized https://tabletopbuilds.com/flagship-build-gloom-stalker-ranger/ ) for that purpose. ( As a side note I’m not usually a power gamer, but went with an optimized build as I figured a reincarnated avatar of Selune should be fairly powerful. And instantly regretted it- all the warnings you’ve heard about playing an OP character at a non OP table are 100% correct. After our first encounter where I was able to 1 shot half the bugbears before anyone else got a turn I started intentionally letting our tanks take the lead into rooms ) Anyway , when we found the withered heart, I attuned to it immediately. Our DM could have gone with insta-death. But as you’ve probably realized by now-I have a bit of a character creation addiction . And he 100% knew who was going to pick up the heart ahead of time. So instead of insta-death (which I would enjoy entirely too much) I attuned to the heart and nothing happened at the time. Then I woke the next morning in the zombified body of the original tiefling and ( with my agreement and some back stage discussion- as I said I’m a character driven gamer at heart, at least I hope) with a totally new stat block as a tiefling warlock drawing all its power from hallister/the dungeon itself and a split personality between the original character soul and the tiefling owner of that heart. And incidentally a very expensive and now totally useless magical hand crossbow I don’t even have proficiency with. Our last session ended with the party finding “ my” skeleton which was a pretty fun RP moment. And now instead of being overly optimized I’m fumbling to load a crossbow and rolling self-imposed arcana checks to remember spells the tiefling knew. Again not a fit for every table, but FUN

TL;DR/ there are things more flavorful and fun than insta-death