Here we have some of the old Stage 1 fusions that are ultimately responsible for the two alicorn fusions that you see here
Summer Bodies And Busts 1 By Lurkingtyger By Bigon by bigonionbean
. Starting with Princess Morning Star, the fusion of Twilight and Celestia being quite the specimen of a mare already. Though her Twilight half tends to remind everypony that behind that physically mature and well shaped mare is the blend of both student and teacher, with even the temptations and youth of Celestia being revealed somewhat by the injection of her students own youth and inexperience. A mare split sometimes between the dual duties of wielding one of the elements of harmony and simultaneously wielding power of Equestria's sun, Morning Star struggles yet also acts with grace and level headedness when the time is needed. Solving and comforting the ponies of her nation despite half of her own inexperience coming to light. Though if given enough time, the introverted nature of her Twilight half is eventually coerced into embracing her duties and social skills that her Celestia part brings her, giving Morning Star the tools to deal with her charge as princess. However despite all the cake, reading and coping, such cannot account for her current predicament that is her love/crush for a certain hunk of a stallion that is Fast Hooves, the poor mare melting mentally at the thoughts whether due to her Twilight half never experiencing such thoughts before, or Celestia having not engaged in such thoughts for literal millennia.

Despite this, her sister fusion and fellow princess Luminescent love is all the more happy to play around with her sisters emotions. A chagrin of experience and taunting lines her muzzle as she prods and pokes at the love that she knows thanks to her Cadence half is potent for the stallion that poor Morning Star is in love for. Lumy gaining many hours whether asleep in the dream world or awake to harness the fusion of her skills, being both princess of the night, moon and of the essence of love itself. Such a blend has resulted in the more romantic (and dare say saucy) elements of dreams and thoughts becoming ever present and detectable to her powers, her sister of course being an ever fun target to poke and prod at. She herself enjoys the company that she enjoys with her own lover Home Defense, the stallion being of course on her mind through the Cadence part of her, with her Luna half learning to grow an attachment to the Big Macintosh half of Home Defense.

On the other hand we have the two mares that make up Queen Motherly Morning, the first being Zap-Apple Jam. The earth pony/pegasus fusion of Applejack and Rainbow Dash only reasoning to give the mare such namesake that makes sense. A mare split between passion and responsibility, ZAJ tends to keep herself busy round the clock while simultaneously attempting to not want to labor through the day. Managing an apple business whilst also pursuing a career as one of Eqeustria's flying elite the Wonderbolts is all around certainly no easy feat. Her mind split one moment between maintaining the roots of her Applejack's side of family's lineage and passion for the fruit of their namesake, and the potency and drive that her Rainbow Dash half seeks to gain through her skill and prowess as a flyer. Though ZAJ admits, she isn't exactly the Wonderbolt material of her pegasus half (that plot being a certain reason) and has learned to adjust her priorities accordingly in order to satiate both desires and goals she has set within her shared mind.

Besides her and all the more the embodiment of fun, magic, entertainment, and curiosity lies the mare that is Sunbutter Cookies. A little bottom heavy no due to a healthy diet that suits her namesake, Sunbutter is a flurry of emotions that her Pinkie Pie half tends to carry with her right over the poor Sunset Shimmer half of her. A blender of talents and prerogatives that can not stay still, she tends to stop herself from anything that requires any more focus than the immediate. Studying time....difficult, relaxing....don't make me laugh, improving her magical prowess...very funny. Though if it has to do with sweets, parties or all of the above you can bet your ass she will be there attempting to be the life of the party one way or another. Though despite this and the energy the earth pony within her gives, she will eventually calm down and find time to give her Sunset half a free reign in doing what she would desire, and thus allowing Sunbutter to further improve her magic and knowledge furthermore...

Done by Lurking-Tyger