Strategy:Halls of Carnage

0.9.9.7

Hurt Me Plenty / Ultra-Violence

Keep a homing phase device in case this level appears. If it does, grab the mods near the start, kill all the lost souls in the middle section, and then immediately use the homing phase device to teleport straight to the stairs and grab the BFG 9000. Once the BFG is secure, you can either test it out on the Barons outside, or wait on the stairs while the other monsters die in the lava. The doors on this level are locked and can only be broken open with attacks.

Beware once the lava starts reaching you, since the Barons will not immediately die and may get to attack you unless you shoot them.

If you don't mind not getting 100% kills, you can leave right away. Otherwise, be sure you killed the lost souls, as they will not die in the lava. If you missed any, you'll have to have at least two envirosuit packs to go back and get them if you don't have some form of lava-proof boots, and since the lava destroys everything but the stairs, they'll scatter about all over the map. Unless you want their ammo, you can run past any formers that aren't directly in your way, since they'll die in the lava very quickly.

Note that this does not necessarily work on HNTR, ITYTD, or N!, as on those difficulty levels there are cacodemons that are also immune to lava.