After attempting the challenge dozens of times, JerValiN finally managed to finish it with expert knowledge of Halo 2's campaign systems, clever use of glitches and skips, skillful and methodical play, and a touch of luck.
Halo 2 LASO is notorious for being significantly more difficult than any other Halo LASO campaign, largely due to the fact that with all Skulls activated on Legendary difficulty, enemies do insane amounts of damage and the player has barely any health at all.On top of that, the combined effects of all of Halo 2's skulls severely disadvantage the player by taking away their heads-up display (HUD) and weapon viewmodel, preventing them from recharging their shields without getting melee kills, and reducing the amount of ammo they can carry.
Halo 2 is also widely considered to be terribly balanced for Legendary difficulty in general (I'm sure you've seen the Sniper Jackal memes).
Halo 2 LASO deathless is arguably the hardest challenge in all of gaming, but in a dazzling display of skill and finesse, one man has proven that it's not impossible.