If you have removed Clover's EFI folder contents and now can't boot OpenCore, boot your PC using your Clover UniBeast installer drive. Once at the desktop, remove the kexts - FakeSMC.kext, NullCPUPowerManagement.kext and NoVpaJpeg.kext, then rebuild your kext caches with Terminal command: sudo kextcache -i /
Once done UPDATE your Lilu.kext and Whatevergreen.kext to the latest and place them in EFI/OC etc. If they were in L/E remove and rebuild kext caches as before. The ones you have in place are too old.
I do not understand why you need "Legacy_USB3.kext or AppleMCEReporterDisabler.kext but at least they are not enabled.
Finally I'm only guessing, but are you using System-Definition MacPro5,1 ? If so, don't. Use a later iMac one, say 14,2.