Dragoon X Omega II Tips from Sliver X

The Zefroom is what allowed you to cure the people of Endengard from the Varion's poison, so you have no other use for it.

There are three areas post-Railjet that require certain things to enter:

The Ice Lab (The northernmost dungeon on the world map) requires the EMP to short the force field blocking the entrance: This is located in B1 of The Armory (A dungeon inset into the mountains from the rails, southeast from the Ice Lab).

However, the Teleporter in the bottom that leads to the Ark needs the Source to be powered on. This is located in The Deadpool, which is reached via a tunnel at the extreme east of the rail system. In this tunnel, the path branches in two: The left tunnel has a switch in the wall you need to activate to lower the bridge across the lake beyond it.

The last is the Nuclear Plant, which will not even allow entry from the world map (Because it's full of lethal amounts of radiation from an ancient meltdown). You need an item called the "AntiRad" to prevent radiation poisoning, which is gained by doing a series of item trades...

The Watch: This is located in the bottom floor of the Marsh Temple (Where you first fought Tyris). If you look at the floor, you'll see a section with off-color tiles in the shape of a north pointing arrow: Push against the "pit" where it points and you'll find yourself in a hidden corridor. The Watch is at the end.

Purify: Give the Watch to a man named Tao in Pergador, and he will give you this item.

Picks: Give the Purify to the elder of Sansia, and his father will give you a set of lock picks. These allow you to open doors in Hylis Keep, Endengard and Arternus Keep. In Arternus, you find the AntiBio.

AntiRad: Give the AntiBio to the nurse watching over the sick girl in Isenfort. She gives you the AntiRad in thanks.

There is a reason getting into the Nuclear Plant is so convoluted: It's a bonus dungeon, filled with soul crushingly hard enemies. The boss located here (Pyro) is more powerful than the game's final boss, but if you manage to kill him you gain the Omega Rifle and Gamma Armor, which make Sargon a walking god.

I'll give you some tips on this. Pyro is a cybernetic enemy, so if you kept the Pulse Rifle you can do quad-damage hits. Couple this with the level 7 PSI Blitz (Two hits per attack) and you can hurt him badly. Be forewarned that he has an instant death PSI called "Fall", which can be countered by using the Medula Implant.

You'll find the Medula Implant on the skeleton in Endengard's cemetery. Grab it, save, and attempt to fight the "woman" who's in there. The SheBitch is a litmus test for Pyro (She is the only other enemy in the game with the Fall PSI): If you can kill her, you have a fair chance of taking down Pyro.

For the Level 7 and 8 PSIs, you need the Nanite upgrade. The Nanite itself is located in the Armory: There's a patch of dark blue stuff on the ground at the northern part of the map: Search it. Now take it back to the Sleg Mine (Where you activated the Railjet) and give it to one of the robots, which will create non-Neverborn-tainted nanomachines and implant them into Sargon's body.

The Level 7 PSIs are in Sansia, while Level 8 are located in the Uris Desert. Near the beginning of it, there's a lone grove of palm trees in front of a cliff face: Search it and a cave is revealed, where the last PSI trainer is located.