In 2012, I published Lyra and Bon Bon's Odd Jobs. One of the OCs in the story was a mare named Radiant Hope. In a recent My Little Pony comic from IDW, they introduced a character named Radiant Hope. She's featured in the comic which reveals King Sombra's back story.

I haven't read the comic, but it's same to assume that the two Radiant Hearts differ in at least one respect. The IDW version of the character probably wasn't threatened with a semen-filled balloon.

He became the tyrant with a stair fetish because they called him weird. You show them sombra. You show them all.

~Have a good one.

Heh, it's like how I had a friend named Cloud Chaser on here that named his OC before Hurricane Fluttershy.