Solaris

Queen High Noon Deus Solaris Daybreak, Sol Invictus

she/whatever  - genderqueer "cis" Mare - bisexual - fully ascended alicorn - 7,500+  years old (calls herself 52 since that's how old she was when she  ascended)

as a person, solaris is, well,  the sun. from a distance she is kind and warm and loving. up close she  burns with anger and rage and things like that. she's a very good  politician, but she's a farmpony at heart and hates being good at  politics. she's extremely confident in herself - she has millennia worth  of experience doing all sorts of things. she's very extroverted and  likes hanging around people. she has an accent that we'd describe as  highland scottish. surprisingly dislikes being treated like a god,  enjoys living life as the average mare even if in her true power she is  Absurdly Overpowered.

solaris is  technically queen of equestria, along with her partner artemis (well,  partner sort of, she and artemis have... Things going on). however,  after the nightmare moon incident she was mostly cut off from her power  thanks to the elements of harmony being overprotective and she refused  to live in the castle's basement in retirement/as a dirty little secret.  so, while celestia is princess-regent she has been traveling around the  planet as a pegasus named high noon (a translation of her name from  back when she was mortal). a couple years before the show she wound up  in ponyville with a magic hunch that Things would happen there.  presently she has a share in the sweet apple acres co-op and lives with  the apple family, doing her share of the work and getting along very,  very well with applejack.

the tl;dr on her  backstory is that about 8 thousand years back an old empire  accidentally inverted/destroyed the sun equestria orbits around and  hastily replaced it with a clockwork/magic/rock substitute. the machine  used to raise the new sun and keep it in orbit around the planet sapped  the magic from the ponies forced into using it. solaris was a pegasus  cloud rancher (how clouds were made prior to weather factories) with  like. a wife and a family and stuff. one day the sun hasn't risen so she  speeds off to the capitol to figure out what tf was going on,  performing a sonic rainboom in the process, and discovered extremely  understandable protests and riots against the use of the sun and moon  machines. unfortunately the sun still needed to rise so she did it  herself, ascending to alicorn in the process. unfortunately she was then  captured by the government who couldn't have the sun out of their  control, so she was kept in a tower and used as a political pawn for 500  years until she completed her ascension, gaining true immortality in  the process, and promptly went full holy fire on the place. she raged  for twenty years, sun and moon under her command and creating the  badlands in the process, until the mare who would become artemis managed  to calm her with a lullaby and treated her kindly for once in her  miserable life. she handed artemis the moon, and artemis raised it,  ascending to the alicorn of the moon in the process.

her  eventual relationship structure looks like a) her and artemis' Secret  Third Thing Millennia's Worth Of Do Not Separate Them marriage/divorce  thing b) her gf applejack and c) their joint bf shining armor after him  and cadence's eventual divorce arc

also  celestia and luna were born ~1700 years ago :> solaris was... mid as a  parent she has Issues with parenting. more on celestia and luna's  childhood later.

she doesn't have a cutie mark because as a fully ascended alicorn her whole body is her cutie mark! also i hate designing them.