Many important questions are still vexing fans of Gundam Double O after Episode 25. Many are concerned with the whereabout of the remaining Meisters. Did Setsuna died? What happened to Allelujah and Tieria? We get to see plenty of stuff to anticipate in Season Two during the epilogue, but it said nothing about the characters right after the war.
Perhaps you can get some hints about that from the June issue of Gundam Ace 00F manga. Since its story runs in parallel with the anime's time line, it seems that the characters from 00F were involved (some how) after the final battle.
More misfortune for Patrick as he encountered Fon Spark's Astraea Type F.
The last page of the manga... Tieria's fate is....?
More scans on Gundam 00 Live Journal.
Not to confuse or mislead you, NOTHING is really being confirmed or explicitly mentioned in the manga. We only get a bit of hints about Tieria's fate and the GN Furnace ejected from his Nadleeh. The whereabouts of Setsuna and Allelujah still remain as mysteries...
Also, it seems that this issue will be the ending of 00F First Chapter as well. The Second Chapter will begin together with Gundam Double O Season Two I presume?