MAP10: New Front Base (Strife)

From Doom Wiki

This level occupies the map slot MAP10. For other maps which occupy this slot, see Category:MAP10.

After the Programmer is destroyed, MAP07: Castle is replaced by MAP10: New Front Base.

Basically, it is a replica of the Castle, only a little different and controlled by The Front. Access to the Training Facility and the Keep are now blocked, and the entrance to the Audiance Chamber is replaced by an HQ where Macil resides.

Just across the HQ is the hospital where you can find the medic Gerard and the trainer Feris, as well as a guy named Justin who sells ammo and Teleport Beacons.

Near the main gate that leads to Town is a teleporter that leads directly into the HQ. You can also access the New Front Base from the Borderlands via teleporter that also leads to the HQ.

Later in the game, Macil becomes a boss you need to kill.

Killing Macil can be easier if you have three Sigil pieces rather than two. Trying to kill Macil and then his Spectre can result accidently killing other Rebels. One reason is often stupid AI and the fact that they almost always get in your way. You could even try to use them as meat-shields against Macil's attacks if you will. Another reason is the Sigil's wide-spread attack when you have three pieces.