As the episode opens, Kamui says his final goodbyes to Kotori. Sorata shows up to offer his condolences and apologize for not being able to help. Kamui responds by saying that his lack of trust in them was what led to this and that he was going to start doing so.
The other Dragons of Heaven also show up and they all pay their respects before going into another introduction sequence. It is justified as there are people who hadn't been introduced, but the frequency at which we see these things is rather bizarre.
A man shows up and tells them that they need to seal the divine sword and leads them to an underground compound where they will house the weapon until the time comes for Kamui to wield it. It is also explained that the two swords are linked and that sealing this one will also lock the power from the other one.
It's a fairly eerie scene as bright beams of light shoot up into the air, alerting the Dragons of Earth that the weapon is sealed. Oddly enough, Fuma isn't too concerned. You'd think that his weapon now being powerless would leave him a bit miffed, but I guess he knew that it was going to happen. Just as the Dragons of Earth came together, so too do the Dragons of Earth, bringing the two teams together, fully assembled, before the final showdown.
Kamui and the Dragons of Heaven go to visit Princess Hinoto, where she explains the specifics about Kotori's fate. A lot of it is stuff that both Kamui and the others had heard before, but Kamui does learn that his decision had no bearing on Kotori's fate. If he had chosen the other side, than his personality would have been over-written and he would have been the one to kill Kotori. Either way, she was destined to die at the hands of the Kamui of Earth.
It sets a pretty bleak picture as it really hammers in the fact that nothing that they do matters. Things are going to happen, no matter what. Kamui, interestingly enough, rejects this and vows that he will not only choose his own future, but he will get Fuma back as well.
In addition to destiny, trust seemed to be the major theme of this episode. Kamui learns to trust his allies, his confrontation with Hinoto relies on her servants trusting both of them and Kamui trusting her when she reveals the true nature of the tragic fate of Kotori. It should be noted that Kamui does appreciate her honesty.
I have to say, I actually don't mind Kamui now. His character is far more likable than he was, but only a few episodes ago. He really has grown a lot as a result of these events and it made him a much stronger protagonist.
With both sides united, it should be interesting to see how the war for the future of Earth plays out from here.