Elena is hinted to end up with a foreign prince. Or at least that's how things were projected to be when the story ends. Said foreign prince is also slated to become the head of state of his country much like Elena ends up, so its implied they might end up making the strongest alliance on the continent.
As for yuri side of things... Aria is pretty much ends up with Carla. After killing and then reviving her, Carla more or less follows Aria around doing jobs and work with her. Besides the fact these 2 are the most powerful beings on the continent with a "pet" super beast that can take on dragons... It pretty much a couple and their cat doing random stuff.
