Greatest successes were many years ago
Greatest success during this war were that we were able to stay pretty much untouched for 2 years against several realms. These few battles we won were just few battle victories.
As for why Darkans have not returned to Darka after Azzal moved to Talerium, i think they know their future is there, while Darka future is pretty much written already, date just have not yet printed up.