His art is one of the reasons why I loved Green Lantern: Rebirth so much. The other was Green Lantern: Rebirth was GENIUS in its use of already established continuity.
Johns first used the Moore/Gibbons’ “Tygers” prophecy from Tales of the GLC Annual #1 1984 (where the Guardians first erased their memories of all of the pain, suffering and emotional stress they endured after a thousand years of torture by the Empire of Tears during the war between Orderly Science and Chaotic Magic at the dawn of time) to explain why the Guardians had no memory of the Yellow Impurity that had been inside of the Central Power Battery for thousands of years (and the reason why the rings couldn’t work against anything yellow) also being the Parallax Entity (because after their first initial encounter and subsequent fight against the Parallax Entity the Guardians defeated it, imprisoned it in the Central Power Battery, and then erased their memory of it because their fight was the first time the Guardians had felt “fear” since their torture by the Empire of Tears)
Then Johns used GLC #221-224* where Hal first entered the Central Power Battery to fight Sinestro from the dead and reveal that the Yellow Impurity that bonded with Sinestro's ghost inside of the Central Power Battery after his execution and that Hal had been exposed to in GLC #221-224 during their fight inside the original Central Power was also SENTIENT/the Parallax Entity.
From there, Johns uses that encounter in GLC #221-224 to explain away any erratic behaviour and/or out of the blue changes to Hal between GLC #221-224 and Green Lantern: Rebirth as being infected by the Yellow Impurity/Parallax Entity.
Yeah GL: Rebirth, brought back and exonerated Hal Jordan, but it also brought back Sinestro from the dead, made Guy Gardner a GL again and brought back the entire GLC with a HUGE BANG after 2 big time miniseries (Rebirth and Recharge) that were selling in the hundreds of thousands!
The best thing to me, though is the effective use of continuity.
*Also, GLC #220-224 was the same story that O'Neil used to plot his version of Emerald Twilight that Marz scripted. That's why Rebirth made perfect sense to us long time GL fans and why I don’t even think of it as a retcon.