You look here this arc is my absolute favorite thing to ever happen to MLP canon. You're telling me there's a shattered glass universe CANONICAL TO MY LITTLE PONY. You're telling me there's a universe where THE GREAT AND POWERFUL TRIXIE IS THE ELEMENT OF HUMILITY. YOU'RE TELLING ME THERE'S A VERSION OF KING SOMBRA THAT CELESTIA IS IN LOVE WITH ?!?!?!!??
I am utterly feral over this universe.
So please say hello, to Mi Odia Cadenza. Instead of her name saying "love", this Cadence's says "hate"
Her talent? Breakups. She is the literal anti-M!Changeling. While the insect race feeds on and spreads love, Cadence saps it. However, she doesn't feed off of it, instead, she uses it as a magical boost, the more she drains the more potential her magic has.
This Cadence doesn't keep Shining Armor as a husband, but rather, he is her slave. He was enamored with her when they were young, and when she discovered her talents, he stayed with her, hoping that a positive influence would help keep her from trodding the same path as her aunt. But in the end, she just drained every inch of love from his body. Now, he stays with her out of sense of obligation, still thinking he can fix her. She's amused by this (it's one of the few things that gives her happiness, as twisted as it is) so she keeps him alive.
M!Cadence does resent M!Celestia and M!Luna for their more dominant role in Equestria's terror, as she believes most to have forgotten she exists. But she is plotting, planning to overthrow King Sombra and take ownership of all Equestria! We'll see which is the "lesser evil" then...