Here's how Brian's nightmare goes in Revenge of the Nightmare Family & Changling Queen.
[Later we come to a dream world and Brian is running to something]
Sylveon: Brian! Brian!
[Brian looks down and sees Sylveon hanging from a cliff]
Sylveon: Help me!
[He reaches down to grab her, but we see Ernie laughing towards him]
Brian: Sylveon, just a little further.
[She tries to grab him, but..]
Ernie: Trust me!
Sylveon: [starts sliding] Brian!
Brian: [as Simba (adult)] NOOOOOOOO!!!!!
[She falls down into a pit of lava]
Brian: [turns back] Ernie!
[However when Ernie laughs it transforms to him!]
Brian: [gasps] It's me?
[Brian's clone kicks him down into the pit]
[However before he touches the lava, he suddenly wakes up panting and looks around and everyone is fine. But he walks down the stair as Sylveon wakes up]
[Later Brian is outside watching the moon]
Sylveon: What's the matter?
Sylveon: Come on, just tell the truth.
Brian: It was a dream.
Brian: Just like the ones I had, when I was trapped in Jumanji.
Brian: And, it was about you.
Sylveon: Tell me.
Brian: It was only a dream, alright? [walks foward but stops and turns back] You died by falling off a cliff, when I was trying to save you. And Ernie was there, but he turned into me, and kicked me down into a pit.
Sylveon: He was you?
Sylveon: It was only a dream.
Brian: I won't let this one become real.
Sylveon: Look, you're in charge for the Grand Galloping Gala. You've been giving a great honor, and if the Council finds out we're still in love, you'll be expelled....
Brian: I know, I know.
Sylveon: You think, you want Thomas, Twilight, or any of the others to help you?
Brian: I don't need their help. The new Grand Galloping Gala is a blessing. [he goes inside]