Turtle Pokemon... I'll assume you mean Squirtle and not Turtwig, since you mentioned Water-types.

[Also, Turtwig is a tortoise.]

Well, that's definitely a decent choice. Which other one are you talking about, though?

[She'll mention the fact that she has, indeed, done just once she's more or less figured out Rainbow's plans for the next few days.]

Ah, yes, Pichu, or rather its evolution, Pikachu, is one of the most popular, not only of the electric types but of Pokemon in general.

... I'm not quite sure why though. It's good, don't get me wrong, you definitely made a good choice, but personally I prefer my Magneton, Tesla when it comes to Electric types.

[... Twilight, it's because Pikachu (and Pichu, and Raichu) is adorable, and Magnemite and its evolutions are floating magnets with giant eyeballs. Well, except Magnezone, which is a miniature spaceship with giant eyeballs. Either way, not cute.]

If you say so. [She's not so sure popularity is necessarily a good thing, but she knows Rainbow likes it.]

I can show you Tesla right now, if you like.

[Just as well, really. If they all had the same Pokemon it would get confusing.]

You do raise a good point. Well, here we go!

[She tosses up one of the balls, and out pops her faithful (and just slightly unnerving. Those eyes never blink.) Magneton.]

Say hello to my friend Rainbow Dash, Tesla.

[The response is a series of unintelligible beeps, buzzes, and clicks.]

Pleasure, Blaze.

[Tesla beeps again. It's completely untranslatable, even to other Pokemon. Poor Tesla just can't communicate.]

So, you were saying earlier that you'd already left Cherrygrove?

[FFFFF. "Hello sir, I am C-3PO, human-Pokemon relations"]

Just about. You'll be about a day past the halfway point when it turns from Route 30 into Route 31 and you see the entrance to Dark cave. Careful if you decide to check it out in there, by the way, it's full of Geodude and Blaze will be weak to them.

Anyway, if that's where you are we'll probably be arriving in Violet before you, so we'll set things up. I beat Sabrina already and got the Fly HM, so it's just a matter of flying Spike over there. We'll be together quicker than even I thought!

[You better believe it! Twilight: 5. Non-Twilight Ponies: 0.]

We don't need Pinkie to celebrate having you join us, Rainbow.

Besides, we have to get ready for Hearth's Warming Eve, don't we?

Well, we'll just have to make do this year, I guess. Unless Johto decides to bring her in at the last minute. I'm sure we can put something together for just the three of us, even if it isn't... quite what she'd be able to pull off.

She's desperate to see you. It's adorable how excited she is, really.

Not that I'm not excited, mind you, but... well, she's practically beside herself.

[She smiles fondly, but there's a tinge of sadness in her eyes. Weird. Something she's not telling, perhaps?]

Ever since flight camp, right? [She knows that much, and not really any more besides the whole race story.] I'm just glad you're here for her now. I don't want her alone here. Not again-

[And she immediately shuts up, as if realizing she just said too much. "Not again"? Now what could she mean by that?]

I'd... rather like to hear that story, actually.

[She sighs and rubs the back of her head.] Yeah, it... frankly, it's probably not my place to tell it at all, but I'm not really sure that she will.

I guess I can probably tell you that she was alone here for a while.

Actually, the last time we were all gathered here, I was the last to arrive. She's been here so long that when I came was the second time she's had us all together with her. Of course, none of us remembered the previous times we'd been here.

[She'll just allow that, along with the implications, like Fluttershy having to watch them all vanish on her, one by one, to sink in.]