The being known only as the Engineer is a brilliant scientist. A scientist that may be an equal or better then Brainiac. As for an engineer goes he can create manipulate anything. He spread terror through out the universe by creating these things call Xenomorph that when unleash are hard to stop. Even Batman had a hard time stopping them.So when it comes to make Sinestro ultimate weapon to annihilate the Green Lantern Corps.The Engineer found the Green Lantern known as Perdoo and experiment on him by crossing krypton DNA with him.Creating something more bada$$ then before.Perdoo did get away and run back to the coop to let them know what Sinestro was planning. The Corps are know planning for another all out war with The Sinestro Corps again.