Superman Earth One Villan

Who supplied the weapon to blow up Krypton in Superman Earth One? Does anyone know?

Brainiac? Idk I haven't read past the first volume.

Still a mystery. Some say Darkseid, some say Brainiac, some have even said it was perhaps Mongul. Zod is the centric antagonist for Volume 3, so it's very possible the culprit will be revealed, or at least further alluded to.