Dear Princess Twilight Sparkle
I know what you really are, I have no intentions though of revealing it. Me and my five allies are sending this as a matter relating to the return of the Shadow King (or rather queen) currently known as Black Shard. As this material is sensitive, the six of us will only tell you to meet us in your castle's library at noon tomorrow.
I urge you to be there on time, as I don't want to send a scout to hunt you down. I will be honest here though, there is no way I'm letting you skip out on this meeting.signed
Night Wind, strategist of the SSF
P.S: I am aware that you are no doubt concerned about my secrecy, but I assure you that it is a necessity. Either way, I am willing to talk freely of my race (Changelings) to you when this is done and will answer all your questions regarding them truthfully. But only if I see you at this meeting.
Dear Rainbow Dash
You already know me, of course, but that doesn't matter. I request that you meet me and my group (not the normal one) in the Harmony Castle library at noon tomorrow. I will not mention your secret within this letter, but when you see my name then you'll know that I know it. Anyway, the matter of which I wish to discuss is one relating towards the issue of Black Shard, why she hasn't attacked yet is still beyond me. I have been told by the designated leader of my current group not to reveal the details of what I want to discuss until the meeting.signed
Absentia, member of the SSF
P.S: I will only talk more about our awkward encounter at our work after you show up to this meeting.
Dear Apple Jack
I know you, but I was told not to reveal myself just yet. I know your secret (the really dark one that involves ancient legends). My group (not my normal group) leader has planned a meeting tomorrow at noon in the Harmony castle library, you are absolutely required to attend. This meeting is one that regards Black Shard. I will be among five others that are the ones planing this meeting. I can't say anymore.signed
Blood Bloom, member of the SSF
P.S: This is a mandatory meeting
Dear Pinkamena Diane Pie
You don't directly know me, but I know you. I know what you hide. Anyway, there is a mandatory (for you) meeting in the Harmony Castle library tomorrow at noon. This meeting is regarding the recent return of the Shadow Demon Black Shard, formerly known as Sombra. I can't give you any details until the meeting begins. This is an important meeting so don't miss it.signed
Lunar Fire, meeting/party planner for the SSF
P.S: Please bring some cupcakes. I, personally would like some made from the ingredients in your basement (If you know what I mean)
Dear Fluttershy
I know who and what you are. My group is having an important meeting at the Harmony Castle library tomorrow at noon. This meeting will be regarding Black Shard's return and is not something I'll allow you to miss. Come prepared though as our discussion may make you thirsty (You know what I mean by that)signed
Shadow Vine, leader of the SSF
P.S: If you come to this meeting then I will be willing to help you learn more about the creatures in the Everfree, I know that you love animals.
Dear Rarity
You know me well, and now I know your dark secrets. There is a meeting tomorrow at noon in the Harmony Castle Library, you have to come. This meeting will regard Black Shard, so don't miss it. My group will be waiting for you. I will warn you that some of what we talk about might make you thirsty (You know exactly what I mean)signed
Circuit Board, member of the SSF
P.S: I actually have several thousand ideas for interesting new styles, I'm willing to share them with you and let you take credit, but only after Black Shard's defeat, which you must come to this meeting to be able to do.