This is how The Overlord timeline goes in My Little Pony Transformers Prime: The Cutie Re-Mark.

[Twilight, Optimus, Spike, and Starlight arrive in a mixed-up Equestria]

Twilight Sparkle: Huh?

Optimus Prime: What?

Spike: Equestria's all mixed up.

Starlight Glimmer: And I think I know who's behind it. [points to something in the distance] Look!

[Twilight, Spike and Optimus see that she is pointing at a black dragon with purple eyes in the distance, indicating that it is the Overlord in dragon form]

The Overlord: [laughing evilly]

Twilight Sparkle: The Overlord.

Optimus Prime: Not possible.

Spike: He's in Tartarus.

Starlight Glimmer: But it seems my brother made it seem like he isn't.

[The Overlord turns and sees them]

The Overlord: Well, well, what do we have here?

[The Overlord approaches them]

The Overlord: Well, if it isn't Princess Twilight Sparkle, Optimus Prime, Spike, and Starlight Glimmer.

Twilight Sparkle: We mean you no harm.

Optimus Prime: We only came here via time travel.

Spike: A pony has the spell for it.

Starlight Glimmer: And we're trying to stop him.

The Overlord: I know who you're after: Nebula Star, Starlight Glimmer's brother.

Twilight Sparkle: How did you know?

Optimus Prime: Did he tell you?

Spike: Did he help you?

Starlight Glimmer: We came here a time travel spell.

The Overlord: I know because I've been shown how it works.

Starlight Glimmer: Well, do you know where my brother went?

Spike: Where did he go?

Optimus Prime: He probably used the spell.

Twilight Sparkle: Tell us where he went.

The Overlord: He went to another time.

Starlight Glimmer: Thanks.

Spike: Let's get going.

Optimus Prime:

Twilight Sparkle: