Lex Luthor obtained a sophisticated alien battlesuit on his adopted home planet of Lexor while he was living there shortly before its total destruction. Subsequently, Luthor used the Lexorian armor in many battles with his archenemy, Superman.
The original warsuit was a LexCorp prototype that Superman was forced to fight. However, due to the fact that the untested weapon drove its user insane, Superman was unable to pin anything on Luthor and was forced to pull back.
Years later, Luthor obtained a specially made warsuit built on Apokolips and used it when his plan to blame Superman for a falling Kryptonite meteor failed. The suit made him even with Superman, but the Man of Steel was able to fight back and disable it. Luthor though used a Boom Tube to escape capture. The second suit found itself in many hands before Luthor regained it. However, it was destroyed by Superboy-Prime.
Luthor designed a sleeker version in his attempt to hunt down the Black Ring.
Lex Luthor had somehow acquired Kryptonian power armor during his shadow conflict with Superman, which he reverse-engineered to enhance the technology his company had created. Around about the time he got out of prison, he began assessing the armor scientists, who had been following a plan of his to buy up companies who were developing technology in the field and incorporating the best designs into a suit of power armor capable of defeating Superman. He was short one component - a solar battery - when the world was attacked by the Crime Syndicate. Arming himself, Luthor put on the almost-complete suit and rallied a group to claim victory, saving the lives of Superman and the Justice League in the process.
After the Darkseid War, Lex acquired a Motherbox and created a new Warsuit based on Superman. When the Post-Flashpoint Superman died, using his warsuit, he decide to take on the mantle of Superman and becoming the new protector of Metropolis.
The various versions of the warsuit have provided the following functions:
- Superhuman Strength: While not as strong as Superman under normal conditions, it can be a match when Superman is weakened by the kryptonite weapons. It can easily overpower Batman and Deathstroke. 
- Superhuman Durability: The alien armor is able to survive direct blows from Superman, however it can still be destroyed by the Man of Steel eventually. 
- Flight: Normally through thrusters in the feet. 
- Force Field: Generation all across the armor and seemingly unprotected head from the torso of the powered armor. Or as an energy shield from the left gauntlet. Combined with the armor itself, it creates enough defensive protection to survive Superman's godly strength. 
- Energy Projection: Lex uses an arsenal of various kryptonites to exploit their ability to weaken kryptonians; allowing Lex to even the odds against the otherwise invincible Superman. With varying affects and from varying locations:
- Kryptonite energy blasts from the gauntlets.
- Green Kryptonite energy generator in right forefinger.
- Red Kryptonite energy generator in right middle finger.
- Blue Kryptonite energy generator in right ring-finger.
- Black Kryptonite energy generator in right pinky finger.
- Blue energy from left gauntlet.
- Electrical surge generated across the armor.
- Energy Blade: Housed in the right gauntlet, made out of kryptonite fueled plasma.
- Kryptonite Energy Spikes: Under armor of the right arm.
- Kryptonite Weapons: Lex sometimes carries around a large spear or axe with the blade of the weapons made out of kryptonite.
- The original warsuit was introduced in Action Comics #544 (1983) as part of the Earth-One continuity. The first New Earth version of the suit debuted in Man of Steel #5 (1986).
- Lex Luthor's warsuit is not to be confused with the LX-20 Body Armor worn by Lex during the years when he was masquerading as his own son, Lex Luthor the Second.
- Appearances of Lex Luthor's Warsuit
- Item Gallery: Lex Luthor's Warsuit
- Images featuring Lex Luthor's Warsuit
Links and References