>>112413793God/Presence, I would assume, sent Jim Corrigan to Purgatory at the right moment to recruit Oliver and prevent his creation from being (permanently) destroyed.
The Spectre is God's enforcer.
>>112413922I guess the other Corrigan from the Constantine show wasn't available and they had to improvise. Helps that they had that line from Constantine, but it burns me, no pun intended, that we got cheated out of resolution from his show's version of Corrigan becoming Spectre.