Lost Ark offers numerous quests for players to complete with each of them providing cool rewards in return. While completing some quests is pretty straightforward, the others not so much.
In this guide, we will show you how to complete The Soul Left in X-301 quest in Lost Ark.
How to start The Soul Left in X-301 quest?

In order to begin the quest, you need to speak to Diego’s mom in Starlight Isle. After you talk to her, she will give you Favreau’s second entry which you need to read to start the quest. Get aboard your ship and head over to Facility X-301 marked on the map above.

After you reach there, everything is pretty simple as you just need to follow the quest markers from one place to another. The only point where things get interesting is when you need to repair B-0031.
You will be required to collect some parts for B-0031 by defeating enemies nearby. The parts necessary for the repair are Steel Diver’s Arm Circuitry, a Steel Diver’s Joint Rivet, and the Secret Base Guard’s Eye Sensor. While finding Steels Divers is pretty easy but grabbing the Eye sensor is quite tricky.
Where to find the Secret Base Guard’s Eye Sensor in Lost Ark?

The Secret Base Guard will drop the Eye Sensor in three different locations in Facility 301 marked below. The enemy has 5 minute respawn timer so finding him can be quite difficult. These mobs can spawn every two to five minutes so you need to check all three locations to find the enemy.
You can spot them easily since they are huge robots equipped with jetpacks on their backs and a large battering ram with blades in their hands. Once you find them, defeat them to grab the eye sensor and then go back to repair B-0031.
You just need to follow the quest markers from thereon and you will be able to complete the quest. The quest ends after you visit Lena at Starlight Isle and you will receive 155 Roster XP, 427 Silver, 2 Lavish Harmony Leapstone Chests for completing it.
Unfortunately, the drop of the eye sensor is not guaranteed so finding the enemy with the eye sensor is pretty hard. We recommend you to play this quest in co-op to increase the chance of receiving the sensor. Because if one player in a party collects the item then everyone else will also get it even if they don’t defeat the enemy.
Try looking for people who are searching for the same item and invite them to your party. After you form a party, tell everyone to reach all three spawn locations. This way you can increase your chances of grabbing the eye sensor.