Through the looking glass part 1
Morningstar smiled as he watches his baby filly rest her head on her pillow. He kisses her forehead in a loving and caring way as he leaves he takes a look back at her and closes the door halfway so he could hear her when she calls out to him for what ever she needed, It hadn't been easy to raise a foal by himself more so sense he himself had it much worse then his daughter, Morningstar often reminds himself that he wouldn't become his father instead he'll give her all the love and care she needed. He makes his way to his room and pulls out his crystal ball and cast a spell on it so he can see whatever he wanted to see, he thought of Canterlot and how everything was doing and the ball showed him a much more different Canterlot then he remembers during his father's reign However he sees an mare reading a book not to far from the palace. Interested he fallowed what she was reading, he sighed deeply when he saw an book titled tale of the two Sisters and in anger he spoke.
"How about you get your nose out of that book you egg head." The mare looked up from her book as if she had just found the answer she sought after, She gets up and heads straight for the palace,the mare who came to know as Twilight Sparkle. Morningstar came to have little respect for her because she negotiated her friends,however his eyes widen with supreme hatred when he sees that his old room had been turned into an observatory. He was almost tempted to curse her had he not reminded himself that he was forgotten to history, he stops looking and looks out his window and looks up where the moon was suppose to be his eyes start to water a bit as he speaks.
"They total worte me out.. Sister, you and I are both relics to an time long forgotten. I wish you where her with me.." He remembers that the spell only bound Luna for a 1,000 years as he smirks and chuckles a bit as he speaks.
"Maybe I can be your ticket out Sister,maybe just maybe tis a full moon tonight" He could hear his filly wine a bit as he vanishes to take care of her for an while. After he took care of Eveningstar he waits for the full moon to appear then he exits his tower, he had to put on a amulet to prevent the change. He flies up into the nightsky with his horn an eerie green glow, he starts to build up the spell as he speaks it in full hatred towards his sister Celestia.
"Nightmare moon unbound I free you on this night so you can have your revenge!" he cast the spell as the mare on the moon vanishes he smirks to himself as he heads back into his tower, however he could feel an cold presence lurking in the shadows all around him. He felt worry for Eveningstar as he rushes to her bedroom, he finds her sleeping like usual as he turns around he sees Nightmare moon standing before him. He hugs her softly as he speaks to her in a happy tone.
"Sister.. i've missed you so much." Nightmaremoon pushes Morningstar away as she gives him an hateful glare,Morningstar could feel the rivalry for mothers love and affection take root. Morningstar began to understand that this thing wasn't the sister he remembered but a monster that feed off of only pure hatred and fear of other ponies,Nightmare moon vanishes right before him and were she stood was his crystal ball. He picks it up as he begins to watch Nightmare moon take her revenge on everything even her former subjects, however he noticed Twilight Sparkle was always at the center of it all. Morningstar failed to understand this but maybe the future will unveil this mystery for him, he looks into her future and with shock and jealousy on his face he drops the ball.
His face contorts into an mincing look, he then picks up the crystal ball again and speaks."Oh, Twilight,Twilight your trials and tribulations start here and now because i will not have an rival for my fathers throne. You don't deserved to be marked as my equal because the thing is your nothing more then a inferior species that my father will always treat as second class." He had hoped Nightmare moon would had beaten Twilight but no thanks to her friends they beaten Nightmare moon with the elements of harmony. Morningstar again failed to understand why however through the course of her life in ponyville Morningstar had an hoof in some of the events his most recent event was him releasing Discord,for an awhile his plan worked however again Twilight and her friends where able to defeat Discord through the power of friendship, He grits his teeth together. In all of his studies of magic there was simply no power higher then the power of magic it self, this power of magic was a abomination in all he knew and studied.
One time he released Cerberus so he could at least see how strong they where with the magic of friendship,although his plan failed although he did find it funny that Twilight would have these wondrous meltdowns of hers. A few years latter he finds another invite to attend his niece's wedding,he raises a eyebrow as he reads the invite fully. His eyes become fiery red with anger as he tares the invite to shreds as he vanishes to go to his room, His niece was going to wed a unicorn of all things. Out of anger he opens up a magical window and speaks to it,he was still angry which is one thing he'll come to deeply regret.
"To any pony in Equestria there's an wedding going on in Canterlot and enough food to go around!" The magical window closes as Queen Crystalis smiles to herself and walks out of her room and heads to her throne room as her royal guards stand to attention. she looks at one of them as he tongue flickered out like an snake,however what she had to say sent shivers down her guards spine.
"Sss.send word we got a wedding to attend."
meanwhile at Suntower
Morningstar was watching the wedding with great interest until he saw the Changeling Queen capture his niece.Morningstar put down the crystal ball and felt deep regret for her but whats worse because of him his niece will be marrying an impostor and everything he had done had little effect well up to this point.
Through the looking glass part 2

Morningstar had heard word that the changeling attack on canterlot had been stopped and the wedding preceded as planed, Morningstar hated to be related by marriage to an unicorn of all things.However sense then he had stopped interfering with how Equestria was suppose to run and like they always say destiny can never be changed, just as he feared Twilight became a princess . Morningstar now has more of deeper hatred then anything towards her but seldomly he interferes with how things are running ,well except that one time he fallowed Twilight and her friends into the castle of the two sisters. He became a black shadow sticking to every dark corner and watched them silently like an ghost,however when he got his cloak became stuck on something he had to leave it behind or risk discovery, the pink one or pinkie as they called her had found his cloak and thought it was funny to try it on. He so wanted to give her an good scolding about taking things that aren't yours,but eventually they left the castle,but not before Pinkie defiled his mothers favorite piano inside her room.
Morningstar was ferrous as he saw them nothing more then intruders,he was almost tempted to curse each and one of them but he knew one day he'll have his revenge. Even though his previous plans to defeat twilight had failed, he watched them with great interest has each one of them had left his mothers castle, he then teleports back to Suntower before he left he gives the old room an passing glace and speaks to nothing but air.
"I miss you Mother, I should have been with you I should've.. Been stronger, don't worry mother I'll destroy these half breeds these inferior ponies that dare claim an pure throne of my Ancestors; There blood will be avenged in blood one day soon." He then teleports away back to Suntower, in a few more weeks it will be the 23 Summer Sun celebration to mark Celestia's 23 thousand rule over Equestia but it will not be what the ponies expect not even Twlights power of friendship would be enough to stop him and his path of revenge.