You can initiate an unlimited number of encounters against Elnoyle enemies in Esthar which is an extremely efficient method of amassing 
Energy Crystals. These crystals are important for:
Ultima magic using 
Forbid Mag-RF.
Pulse Ammo using Ammo-RF.In other words, you will need to stack up a fair number of Energy Crystals during a typical playthrough.
You can initiate the battles against an Elnoyle very easily but it can only be done at a specific point in the game. You can do this when Esthar is overrun with monsters following the Lunar Cry happening at the Lunar Base.
Travel to Area 14 in Esthar and look for a black solider leaned up against the railing of the walkway. You can use the Esthar map on the Esthar walkthrough section to help you find the soldier.
You cannot win Energy Crystals unless the Elnoyle is level 40 or higher, but this shouldn’t be a problem as your characters should all already be level 40 or more. To confirm the enemy’s level, take all three of your character’s levels and divide it by 3 to come up with the average and just make sure its higher than 40.
Remove the 
Mug command as you need to avoid stealing from the Elnoyle in order to have Energy Crystals drop. You have a high chance of obtaining 2, a rare chance of obtaining 3, and an even rarer chance of obtaining 4.
Death status effect, so junction 100 Death magic to 
ST-Atk-J and this will have a chance to instantly kill it with a regular attack.Blind and Poison (or junction these spells to ST-Atk-J) to reduce Elnoyles chance to hit with regular physical attacks. This is especially helpful because Elnoyle will counterattack your party members regularly.
