(Heavily inspired by the following: Power Rangers/Super Sentai, Madoka Magica, Kill la Kill, RWBY & various different hentai which I cannot name presently)
Sunset Shimmer; worried that there magic in its current form may not be enough to combat future magical threats that plague the human world, reaches out to Twilight for an answer to which the pony princess along with aid from her human counterpart, devise a way to enhance and properly and safely weaponize their friendship magic. Each girl in the rainbooms(now including a human starlight glimmer) are given a pendant similar to the one Sci-Twi used at the friendship games adorned with their cutie mark. With their magic super charged each of the girls begins to display amazing magical powers and even get amp'ed up transformations of their pony up'ed forms with the addition of rainbow power.

But of course with new power comes a threat that wishes to snuff it out, can the girls shine their rainbow light through the darkness? Find out!
Trigger Warning: Hentai esque scenes, violence, cursing, alcohol, drugs, death etc...you've been warned. Enjoy!