Lex Luthor. Owner of LexCorp as well as Injustice International LTD. A former Orange Lantern, he's recently returned from the "dead" after sending his mech into self destruct mode.
His LX Sentinels are a particularly nasty innovation. Buying some 616 Sentinels from HAMMER Director, Norman Osborn, Lex first refitted them with krypotonite engines. Four in particular were truly realized. The "LX" standing for "Lantern Cross-pollinated," the machines were designed to have Lantern Batteries serve as their ideal power source.
Teaming with Bullseye, who received a Star Sapphire Ring to symbolize his "true love" (for killing . . .), and Sabretooth, who received a Red Ring of Rage, Lex's greed lead him to take an additional (Blue) ring, and then lead the Negative Three and their Fully Realized Sentinels to terrorize The Nexus.
Now resurrected, he seeks revenge on the two who had a hand in slaying him: Chris "Darkhawk" Powell, and Querl "Brainiac 5" Dox.
Note: I realize that little, if any, of this is canon. It pertains to my portrayal of the character, not the comics version on which he is based.