- Kill your allies at the start to skip dialogue
- Sword cancels in the halls
Focus on killing the sentinels. When all sentinels die in the hangar, the fuel rod grunts will come out. Every enemy in the room has to die for the hallway door to open.
Sword cancel through the hallways, you don't need to kill anything or stop at all.
In the room before the banshees, where the heretic leader says "Deal with him, my brothers! I will defend the Oracle." There is a frame perfect trick called the glass clip. You can see the Heretic leader through the glass, and he stands still right in front of you when saying his dialogue. What you want to do is throw a grenade at the glass so that it bounces and lands on the floor a bit away from the glass, then jump on the window-sill, for lack of a better term. Make sure that you are standing so you are lined up with him completely perfect. Then, while standing still pressed up against the glass, swing your sword at the leader two frames before the grenade blows up. If done correctly you will clip through the glass and be standing next to him and the banshees. Very important, if you do get the glass clip you have to take one of the two banshees that he doesn't take. If you take his banshee you can't finish the level.
After clearing the hangar, make your way to the hallway door. Try to get there before it starts opening. An Elite will either spawn right in front of the door, at the bottom of the ramp, or in an ideal spot between the door and ramp. If he's at the door, you can stick the Elite before he has time to react. If he spawns in the middle, you can reliably get a cancel over him. You can also just cancel off one of two Grunts that spawn with him for any of these encounters. Cancel off the sword Elite, cloak, cancel off another enemy, and enter the next room before your camo runs out. If it does run out, you can stick the Elite near the end of the hallway before proceeding.
From here, you can head up top and jump the rafters (recommended for full game speedruns) or cancel off one of two Grunts below. Feel free to pick up the Carbine along the way if using the rafters. If you get Grunt spawns at the next hallway door, seek cover near the ramp and take them out before proceeding. If you hide beside the door frame after heading through the doorway, you have a small chance to get a checkpoint, if needed.
Heading left and ignoring the initial enemies in this second hallway, turn the corner to come across an Elite who will either be walking up the ramp or running to a spot on the ramp with his back turning to you. If he's walking up, you can cancel off of him or you can sword lunge and slice him to death (neither should alert the two Grunts below) then cloak and cancel off of one of the two Grunts. If the Grunts don't spawn, you'll get a checkpoint. If the Elite's alerted, sword him while his back is turned then cloak immediately, as the two Grunts will make their way up the ramp.
For the last part of this hallway, you can cancel off one of two patrolling Grunts. If you get a bad cancel, you can toss a grenade at the sleeping Grunts behind you. An Elite might spawn near the end of the hallway, sword him to death if he does. When you reach the door to the next room, wait for a shield/camo recharge and perhaps a checkpoint before proceeding. Cloak, crouch jump onto the ledge, and cancel off the Elite. In the next room, stick the first Elite and either wait at one of the two doors or attempt the glass clip. Ideally, you want the door on the right side to open, but it's random. Cloak, get in the Banshee, and fly to the end. If you're being shot at by an enemy Banshee, you can dip up and down to throw off it's aim.