A veritable treasure trove of information was gleaned about Earth-Three from the latter two appearances of the Crime Syndicate, when they battled the Secret Society of Super-Villains and later as they encountered the Justice League, Justice Society and All-Star Squadron (these Syndicators weren't modest in the appraisal of their powers, given the number of foes they encountered at any one time!) For instance, when five felons of the Secret Society arrived on the Syndicator's world, they quickly learned that while Power Ring had the appearance of Earth-One's Green Lantern aka Hal Jordan, he had the weakness of Earth-Two's Green Lantern aka Alan Scott. Specifically, a vulernability to wood, as illustsrated by the Floronic Man's tree shield which the emerald beam should've been able to cut through. Could Power Ring's power battery, originating in Asia like Scott's, have originated from that universe's Green Flame of Life in the form a a green meteorite? Remember, Earth-S had its own version of the meteorite originating from the Starheart just like that found on Earth-Two. Given the similar nature of the energy, defying scientific laws like Alan's ring and the same weakness, it seems likely that this is in fact true. That Power Ring used his alien energy for evil which was not permitted on Earth-Two can be explained away given the reverse logistics of good and evil found in Earth-Three's universe, a trait it shared with the Anti-Matter Universe wherein evil reigned supreme instead of good as in other positive matter universes.
Additional facts revealed from the heroic Captain Comets visit to Earth-Three, in pursuit of the Society, was how this planet's history was dramatically reversed from that of his own (and our's). With America as the dominant imperial power of this world instead of Great Britain and a President John Wilkes Booth instead of Abraham Lincoln, it seemed that each counterpart on this world had a dyametrically different view on world affairs from that of their cosmic twin on Earths One and Two. With the except being the aforementioned (in an earlier post) Lois Lane, who was a heroic reporter on Earth-Three as she was elsewhere. The curious factoid is that no heroes, prior to Luthor, appeared on this world. Such individuals would have corresponded with the Secret Society of Super-Villains and other devious despots.