The second dream sequence is my favorite. On the one hand, it feels like a real dream. She starts off AS the princess (the perspective is notably different from the first dream), but then V appears and she is V while seeing V, and then it’s the video game she played earlier. I appreciate the realism.
But. There’s also a lot this implies story-wise.
Endymion has his sword out. This is during the war, probably actually right before they die. They’re running away from something Usagi’s dream represents with a dinosaur.
And then V cuts in.
There are two things I take from that. 1) Endymion has taken Serenity away from her guardians. They’re probably fighting, of course, and so away from the battle means away from them and that would seem like the safest choice. Heck, Venus or one of the others might have told Serenity to get away. But the point remains, Serenity is without her guardians and when danger strikes, she wants them there. I don’t think Usagi/Serenity wants to remember what really did come next, and V keeps that from happening. If Venus or anyone else had been there, it wouldn’t have happened the way it did.
2) Usagi/Serenity *becomes* V in her dream. Through the video game, she can fight the monster. She can save herself.
And then she wakes up and becomes a soldier for real.
This time, she will save herself.