Perform 4 Neck or Jaw Breaker Glory Kills on the Imp (attack from behind).
The battle after the meeting with Olivia is a good opportunity to complete this challenge.
Searching High and Low
Find 3 Secrets.
Location of secrets can be found in a separate chapter of this guide.
Kill 15 demons using Quad Damage.
The power up needed for this challenge can be found in two locations - during the first battle after meeting Olivia and during the battle with Mancubuses.
Cross the Bridge
Keep going forward after the level starts. You will reach a closed gate. Once you get there, turn right and jump floor below. In the nearby room you will be attacked by demons among which there will be a rocket shooting Revenant. Kill the first enemy of this type from distance, by hiding behind the nearby wall when he starts shooting. Jump down after defeating him and get rid of the remaining enemies.
Go to the room with the door on the left once the battle ends.
Inside, in addition to the medical station and Data Log, you will find Delta V Jump-Boots which allow performing double jumps. You can test them by jumping to the place from which you came.
Jump one floor higher from there (the edge with green lights that is on the right side) and then walk a while and jump down to the left, to the first Rune Trial and to the additional armor.
In order to complete that trial you must kill 30 enemies with Supershotgun. The objective of course has a time limit which becomes increased every time you kill someone. As reward you will receive the Ammo Boost rune which increase the number of ammunition gained from demons and items. First kill all beasts in front of you, then go ahead, jump one floor below and kill other demons. Further path should lead to the right, along the wall. By walking around the location in that way you should encounter every beast. Remember to follow your ears since the beasts howl quite loudly.
Jump down through the nearby hole after completing the challenge and then go to the opposite side of the warehouse. You must climb floor above and then find the platform marked with green light.
When you jump towards it you will see a long pipe nearby. Jump on it and go on it to the left.
Turn left at the end and jump to the niche in which Argent Cell was hidden.
Now you can go back to the place from which you jumped to the platform next to the pipe. Go to the right. Climb up by using the platforms. You will reach a place with two parallel paths. You must use them to walk forward while jumping from one to another from time to time in order to avoid obstacles on your way. The green lights that signalize platforms on which you must jump should make the task easier.
More or less halfway through Imps will start shooting at you. You can take them down from far with a ranged weapon and safely go forward or kill them from close with a Glory Kill performed from behind. The second way will allow you to complete one of the challenges.
Once you get to the end, jump to the path on the left and climb up by using the platforms. Further path leads left, but before you get there you should turn right and then jump on the staircase on the right.
At the top there is a sidewalk leading to a room with demons. Once you kill all the demons you can pick up the Data Log and use the Combat Support Drone.
Then walk outside through the second available door and walk around the room. At the end you will find a green armor. After collecting it you can go back to the top of the path with the Imps and this time go forward.
Walk to the edge on the left after jumping through the wide hole. Look down. You will see the first Elite Guard. Jump down in order to search him. Then climb back up by using the double jump.
Scale the Tower
Further road will lead you to a place in which you will encounter Olivia. Enter the room behind the glass once the short cutscene ends by using the door on the left. Inside you will find another Data Log, medical station and Automap.
Walk through another locked door at the other end of the room once you collect everything. Behind it you will face a large number of demons. You can use the start of the battle to complete the challenge related to Imps.
However, if you completed that challenge, then quickly run to the other side of the corridor and pick up the power up which improves your damage four times (Quad Damage). Not only will it allow you to take down the demons faster, but to complete the second challenge as well. You must only quickly kill 15 creatures.
Go to the end of the corridor once the battle is over and walk through the door on the left. You will get to the room with containers that are constantly moving. Wait for one of them to move and them run behind it and jump to the bottom. From there you can climb on the sidewalk on the left. Turn around before you go further ahead. Behind your back there should be an Elite Guard lying on the ground.
Go forward after searching him, until you reach the place with another Data Log. Now it is time to find the first collectible on this level.
First turn to the right, jump down and then go left. You will reach a container that isn't moving. Look at the wall on the other side after you climb on it. There is a ledge there to which you can jump. In order to do it, most of all position yourself so that you have directly in front of you before you jump. Then wait for the nearby container to move. After few attempts you should succeed.
Once you reach the destination, turn around and look left. There will be a tunnel through which containers are riding.
Once the path is clear, jump inside, run forward and then jump down on the left ledge. There you will find the collectible (Orangeguy).
Now you can go back down, to the place where there was the Data Log. This time go ahead. At the end you will notice a hatch on the left. Open it, walk one floor below and then open another door.
Behind it you will face a large group of demons among which there will be a few Mancubuses. These large beasts can shoot from long distance, use fire and cause shockwaves by hitting the ground. When fighting them it is best to have some cover behind which one can hide.
Quickly run to the right after you kill the first large monster. You will reach a place with Quad Damage power up. Use it well to obtain one of the challenges. If you lack many opponents for that, load the game at the end of the battle and start the battle from the beginning. The previous opponents will count and Quad damage will appear on the map again. The Power up is most effective when used with rocket launcher which has homing missiles. Such enhanced series should kill even the Mancubus.
Once the battle is over, go to the green panel pointed by the radar. Use it to slightly rise the platform and then jump to the right until you reach a similar elevator.
Activate the third machine and jump from it to the platform moving at the wall nearby. You will reach another floor of the tower.
Now go slightly above through one of the sidewalks and use the green-marked platforms to climb to the higher floor.
Below one of two further sidewalks there is the second collectible (Purpleguy). First check on the map under which one there is some space, then carefully jump below and secure the landing with a double jump.
Jump one level higher after collecting the items and go back up. Further climbing will lead you to a place with rotating ring. Wait for it to stop and for a platform to appear. Jump on that platform. Climb there quickly as soon it will disappear.
On the next floor of the tower you will have another encounter with demons. If you have trouble, collect the Invulnerability power up marked on the map. It will make you temporarily immortal. In order to reach it you must use the gravity jumps.
Go to the room marked on the radar once the battle ends. Inside you will find Argent Cell, medical station and a panel that activates special drones.
One pair of robots will be just behind the glass and another is precisely on the other side of the tower. First go to the second pair and jump on one of the machines.
It will take you to a platform with a lever which unlocks the Classic Map below (in the place where drones are hiding).
Use the "elevator" next to the control panel after unlocking the secret. Once you ride up, jump on the closest platform and keep climbing up until you reach the ring fragment which rotates around the tower. When it stops, wait for a short sidewalk to appear and then quickly jump on it. Then immediately get on the construction at the wall.
There you must wait for another moving tunnel (it will appear at the edge of the moving platform) and run through it to the middle of the tower.
Jump between the platforms and parts of the tower that are marked with green lights until you reach the place with Imps and red energy surges. Kill the Imps and watch out for the electricity since it deals high number of damage. In order to get to the other side you must wait for it to disappear for a moment. Slightly further there will be a moving part of the tower which will take you directly to the rooms above. Kill the demons inside and keep going ahead.
Once you reach the place with containers, wait until the path is clear and then jump to the exit on the other side.
Now you can turn around and jump above. However, before you do it, examine the Rune Trial (Equipment Power) below on the left. This time during the challenge you must kill 10 enemies with explosive barrels. For completing this you will receive a rune which increases effectiveness of grenades and similar items. First go to the edge of the location so that the enemies cannot surround or quickly kill you. Then start shooting the barrels near the enemies. Once the center is empty, lure the remaining opponents closer to the walls and blow them up there, trying to kill as many of them as possible with each explosion.
Once you complete the trial, go back to the entrance and jump higher. You will reach a short corridor. Further road leads up through the platforms on the left. However, before you start climbing, first pick up the Mega Health enhancement which will increase you health bar.
While climbing to upper floor you will encounter the last Elite Guard. You should search him.
Once you're above, use the stairs to enter the room with the health station and a Hologram. In replaces the grenade and makes the enemies attack your dummy instead of you. Useful against stronger enemies.
In the same room you will also find an elevator shaft. Further road leads up, but before you start the climbing first look below. You will see an orange edge of a niche inside the shaft.
Fall in its direction and then properly land with the double jump. You will find a new weapon - the deadly, but precision-requiring Gauss Cannon. In order to go back up you must use the nearby panel which will open the door on the other side.
When you will reach the shaft again, jump on the platform above and then turn around and shoot the four brakes which block the elevator. This will unlock passage to the next room.
Collect all the valuable items inside and go ahead. A cutscene will start during which Olivia will expand the hell gate. Your task now is to survive until the level ends. There are many opponents and the location is rather small, so use all area weapons and abilities well. If you feel that there are too many opponents, you can jump outside on one of the rock ledges. After some time the battle will end and you will end in hell.