4. Fatalis (Iceborne)
The final boss of Monster Hunter World: Iceborne story-wise and one of the most challenging experiences in the series. Considering Fatalis’s name lives in legend, and its very presence spells calamity, it’s not too surprising initially…until you’re one-shot by its fire projectiles. Until your health is whittled down to nothing with its firestreams.
Until it flies up in the sky, and you must take shelter inside a ruined castle, or you will die. Even its physical attacks deal ridiculous amounts of damage. The real kick in the teeth? You have only 30 minutes to kill it, and you must do so while solo to unlock the multiplayer version of the quest. The next entry on this is unfiltered nonsense with its settings, but in terms of a pure endgame challenge, nothing tops Fatalis.
