Final DooM/The Plutonia Experiment, map 11 "Hunted"
This f**king level is why I sometimes go by △ r c h ▽ i l e or use it as custom text. It's a literal maze, filled with only Archviles - for those who don't know, the toughest non-boss enemy in Doom 2 and Final Doom, which in addition to a powerful ranged attack, can resurrect fallen enemies, including other Archviles. There's no health until the end, and the end has two exits, one of which is a trap.
Good timing and the super shotgun finally got me through it though.