This is Blind Eyed, the Equinox Counterpart of Diamond Tiara and Zecora. Princess Blackhole, after looking back at Eclipse's death, found out that there will the return of her own sister to seek revenge on what she has done. And it must be stopped by three kin from three different dimensions. He came first as a child before Haunted Knife, who came second as a pony and grew up a poncat after Reese, who came and grew up a corrupted pony. She (Queen Blackhole) made a Equinox Power of Three to stop Eclispe from eternal return.
Here are the reason why Blackhole killed her sister. Her sister was kind and her big sis was jeeeeeaaaaaaaaalllllllllllous!
Character (c) Me
MLP (c) Hasbro