Excerpt from this week's Secret Files:
Once thought to be merely an honorary title in the Green Lantern Corps, Ion is in fact the symbiotic willpower entity birthed from the Green of the emotional spectrum. Its existence was kept a secret from the Green Lantern Corps since their inception, and it resided in the Central Power Battery to keep Parallax in check. Only after the destruction of the Central Power Battery were both Ion and Parallax set free. Ion wandered the cosmos for a time, and eventually was reined in by what was then the only surviving Green Lantern ring, that of Kyle Rayner. Kyle Rayner served as its host briefly, and noted that his powerbase was so greatly expanded, he didn't need a power battery or power ring to manifest the emerald energy. Following its extraction from his body by Sinestro, the Daxamite Sodam Yat was chosen as the new bearer.
Excerpt from your Ion Special:
"What about Jade? What was all that about, telling me her death helped make me Ion?" "Her death was unfortunate, and unplanned. The energies she returned to you enabled you to serve as a temporary host for Ion."
What I get out of this:
The bit from the Secret Files about Kyle "reining in" Ion after it wandered through the cosmos is obviously intended to mean the first time Kyle was Ion, since the same blurb from the Secret Files mentions that, at the time, he had the "only surviving Green Lantern ring" -- hence, this can't be talking about the second time (which was during the Ran-Than War, when the Corps was already back). So he received the symbiote in Vol. 3 #145, it seems like. Now we come to the blurb from the Ion special... putting this all together, this seems to directly imply that the time between when he expended his energies resurrecting the Guardians and reigniting the Central Power Battery and when Jade died, his body wasn't able to serve even as a temporary host so the Ion symbiote either lay dormant inside him for all of this time or somehow remained close to him, waiting for such a time as when it could reinhabit him.
does that make sense to anyone else taking into account the stupid amount of Retcons that have been hitting everything Green Lantern related lately...