Lex utilized a war suit throughout the Bronze age, with the suit becoming one of his trademarks. It had a green and purple color scheme and allowed Lex go fight Superman on a relatively even ground.
This Bronze age suit was last seen, along with Earth-One Lex, in Crisis on Infinite Earths. Typical for its time it was designed with a garish red / green colour scheme that would be given more satisfying tones in modern times.
This suit reappeared in Identity Crisis 2 beinge held by two street thugs.
The new post-crisis suit was first unveiled in Superman/Batman 5, When president Luthor, revealed to be a criminal and gone mad from using the venom drug, uses
it to attack Superman and Batman. The Heroes manage to defeat Luthor, although he disappears via a boom tube.
This armor was apparently created by Darkseid for Lex. It retains the color scheme of the silver age version, but is much more bulky and angular in appearance.
After the Infinite Crisis Lex made some changes to the suit, making it less boxy and more rounded, as well as upgrading it further.. This version of the suit is still in use.
In the wake of New 52 universe 3 versions of the suit have appeared.
The first appearance of Lex Warsuit is in New 52 is Action Comics 17. Despite being stuck in an inhospitable prison Luthor created a improvised radio-telepathy circuit to take control of a battle robot to save Superman from the threat of Superdoom,because he's the only one that have right to killed him.
After Superdoom destroyed part of the armor, Lex loses control of it and apparently seems to be downed due to the mind link being broken.
A second and bulky armor was presented in Action Comics 20,when Luthor infected Superman with a mutagenic virus that contact with his Kryptonian biology eventually become a semi-sentient creature that replicate itself using Metropolis citizens.
Lex planned to get rid of the creature and blame Superman for its appearance and thus become a hero of the city.
A third version very similar tothe Black Ring stroyline have appeared in Forever Evil 2.
Weapons and Abilities
The suit employs Human, Apokoliptian and Kryptonian technology. It is incredibly powerful capable of going toe to toe with Superman, at least for a while. It grants its wearer enhanced strength and durability. It has powerful shields which cover the whole body, protecting the seemingly exposed head, and can sustain several full-power punches from an enraged Superman. Energy blasts which Lex used to incinerate several OMACs at once. Advanced Jets in the boots allow for rapid flight.
For battle with Superman, the suit can fire blasts of Kryptonite from it's right gauntlet. It has several variations of Kryptonite radiation, which are fired through the fingertips. Each finger fires a different kind of Kryptonite.
The Suit also has an a blade in its right arm for close combat.
This not exactly a battle armor, but a robo battle telepathically through a special device can be controlled. The few weapons shown are 50 caliber machine guns,short range missiles and flamethrowers.
The second version is also created by Lex Luthor to get the best of Man of Steel,though he is weakened by red sun radiation and the Hybrid virus. This armor is equipped with sensor systems linked with Lexcorps computers and satellites,the weapons systems consists of short and long range missiles and electrical blasts.
Apparently the suit have a energy shield inside,which enhance it's durability,because the suit proved to withstand heat vision at point blank range and beyond the protection capabilities the energy shield can be used as a weapon, and can even cut durable objects,additionaly have a jet-pack to reach high altitudes in rapid flight.
This is the unique suit that have a helmet.
The armor presented in Forever Evil event did not demonstrate other capabilities besides energy blasts.