While some are trying to world first the no hit version of Elden Ring, others have preferred to try to finish the deathless, including not dying to any boss.
Niko Bellic is the first played which managed to do just that and is already known for his iron mentality on games like Sifu or Metroid Dead.
Niko managed to complete Elden Ring in 2:35 without dying once .
If don't don't spend too much time in the catacombs, and worked on the optimal ways to reach the bosses and the dungeons, clearing the game that fast will not look that hard. Making it deathless can be way harder though as you'll need a perfect understanding of what's hapening and a well thought build to follow-up.
Going that quickly obviously means that you can't spend time gearing your character so you'll have to be ready to fight the hardest boss of the game with nothing much, and still don't die. As impressive as the feat looks, with more time and optimisation speedrunners surely will be able to go even quicker, not even talking of possible glitches.