Dear Princess Celestia,
Recently, I spotted two specimens of a heretofore undiscovered species while calibrating and testing the new telescope I had installed in my castle. Their physical descriptions are included below. Intrigued, I performed some long-range observation and listening, and while the pair conversed of many interesting things a certain word recurred no less than fifteen times. I have done my own research into the term and found little information relating to it, so I write to you with a question in hope you will be able to shed some light on it.
Princess, what's a 'planeswalker'?
Ever your faithful student,
Twilight Sparkle
Little did I know what I was getting myself into when I asked Princess Celestia about that one little word. And now that I know what it means, I've been swept up into an interplanar conspiracy threatening the safety of Equus and countless other planes.
But I'm Twilight Sparkle. If there's anything I can handle, it's ancient evils and magic. I just wish I knew what they wanted.
7660490
Coming off as too info-dumpy was my main worry about this, even after I'd cut out a lot of the conversation. I will point out however that the Eldrazi weren't always a self-contained threat, Sorin, Ugin and Nahiri had to imprison them in Zendikar after all, and that during the events of Planeswalker (Urza block) Phyrexia was on an interplanar robbery spree. I don't think it'd be all that unlikely a pair of veteran planeswalkers would know about them.