Alright soo long story short, Equestria is overwhelmed by a sudden 'curse' it is not yet known what the reason or origin for it is but it has affected all cutiemark owners, tho we will concentrate on Equestrias protectors here, the elements of harmony.
The condition is as follows: ponys suddenly found themselves awoken with a new cutiemark, emblazened between their shoulder blades, said cutiemark representing their 'soul bond' another pony which they are practically forced to be close to. Bonded ponies have to stay close together; otherwise: pain, sickness and eventual death follow. Staying away from their bond is painful, but not just that, intimacy or pregnancy initiated with non-bonded parties generally end in failure including mental,emotional and physical distress.
Basically a soulmates AU but filled with angst woops, bless Sapphi-boo for the idea. I wanted to do something new to get out of my art rut so I threw on a good ol pony randomizer and ended up with the colorful assortment you see above. Cutting the details into seperate pics to avoid a huge wall of text