At the start of the game, you can find a Cyber Elf hidden behind the wall in the back of the room you get resurrected in. You need the Z Saber to get it. Stand on top of the case and do a Jump Saber attack. The other Cyber Elf is in the Resistance Base. Answer "No" when Ceil asks you to help them. Then, take the elevator to the bottom floor and talk to the man who is laying down. Give him the Energy Crystals that he asks for. He will then stand up and you can get past him. There is a room a short distance past him. There is another jar in there that you must use the Jump Saber attack on.