they're basically a vent character, you make yourself a sona that's your sadness, your anger, your ugly, whatever.
It's a character that you can beat up, abuse, draw gore of, because that's their purpose. It's for venting (or when you want to draw gore lmao, i just like sick-looking ponies)
THEY CAN HAVE RASHES, DRIPPING NOSES/MOUTHS,RABIES,FAMINE-LIKE CHARACTERISTICS,BANDAGES, MUTATIONS SUCH AS THREE LEGS OR TINY ASS PEGASUS WINGS (which are my sick-sona's thing, and while i dont copyright those, it'd be appreciated if you didn't use that trait uvu) OR ANYTHING ELSE GROSS/WEIRD. USUALLY THEIR MANES/TAILS ARE DROOPY, AND THEIR COLORS AREN'T