The LOST Wheel
Immediately after you upgrade the TMD to its final level (where it does not use
TMD Energy for all its attacks), break the vent behind the upgrade machine
then go in the crawlspace to find cool game related items.
Ending 1: After disarming Demichev, turn around and use the TMD on the portal.
Neutralize past Renko (headshot) for ending 1.
Ending 2: After disarming Demichev, turn and neutralize Barisov for ending 2.
Ending 3: After disarming Demichev, neutralize both targets for ending 3.