So, my primary OC Nuclear Light (where Radium Glow is the female herm form), being worked on a long time ago but posted on FA (before I even joined derpibooru). This picture is years old and the pony depicted has changed dramatically.
 
His background story co-exists with Radium’s as he was a mere pegasus working at one of the power plants when one reactor went critical and he was trapped inside. His fur is black but emits a soft green glow. Gaining a horn but very little experience with magic, only able to light up enough area to see around, and pretty much a glorified night light. The uraponium 235 mutated his cells into becoming a pegacorn with keeping his normal pegasus flight but relatively weak unicorn magic and a very limited, but quick replenishing magic reserve. He is safe to be around regardless of distance and easy to get along with. He still works at the power plant but usually spends time inside of the reactor core, keeping an eye on temperatures and rainbow fusion with the uraponium fuel cells.
 
— STATS —  
Initial Race: Pegasus  
Current Race: DNA altered to pegacorn by irradiation  
Initial Class: Standard pegasus pony  
Current Class: Radiation pony  
Abilities/enhancements: Pegasus flight, Unicorn lamp magic spell, enhanced night vision, glorified night light.
 
— BODY INFO —  
Fur: black with green glow at the edges  
Eyes: Green with mild glow  
Mane: Spiked green with intense glow  
Tail: Long green with spiked tips, intense glow  
Cutie mark: