Description: a regular sized female Litten 

Personality: An unusually soft-hearted Litten, Radon is kinder and less sassier than the rest of the Litten, especially in the Starter Squad. She tends to be trusting and is fierce despite her softness. She tends to fight harder for what she believes in, believing hard in Barium despite him not being confident enough. She's plenty confident in herself too. She believes hard work is the key to a successful life. Radon can't swim and hates water. However, she enjoys battling and loves to fight to prove her worth. She also tends to have more fun than others and loves to defeat bats. She also has a disdain for humanity. She also tends to be slightly sassy in certain occasions. 

Status: Alive

Goals: To bring back the sun (succeeded), to find Prism (failing), to capture villains (ongoing), to help others in Actinium's name (ongoing)

Allies: Frisk, Actinium, The Starter Squad, Barium, Vesuvius, Lunala, Jab, and more 

Enemies: Kagis, Eiginnte, Tudi, Tisa, Witness, Solgaleo, and more

History: The Radon we all know and love wasn't so nice when she was a child. She used to be cold and distant because her parents weren't so kind to her. One day when she was three, she got into trouble with a group of Seismatoad when she tries to eat one of their baby Tympole. She got pelted by Hydro Pumps and the group was about to end her life before Actinium, a soft-hearted Skelidurge jumps in the way to save her life. Thankfully both survive and Radon treats the Skelidurge like he was stupid for his act of kindness, not knowing that it was his job and that there are good Pokémon like that out there; her fear of water comes from this event. Radon keeps getting into trouble, each time being met with hostile and angry Pokemon as she makes enemies with most Pokémon who go her way, all the while her parents neglect her at home. Sometime after that she was captured by humans and shortly neglected by them. When she was six, she got into so much trouble with a Kleavor when she destroyed her Pokeball to leave her trainer—she was sulking and using Ember on random trees until she unexpectedly hit a Kleavor in the face. The Kleavor chases her and doesn't listen to reason. Actium saves her life once more and even he couldn't keep up with the Kleavor's attacks. Realizing this the Skelidurge orders Radon to run. Radon begins to run before turning back to see the only Pokemon who treated her with any sort of kindness or affection had been sliced in half. She runs away, vowing to make it up to the dead Pokemon. She learned throughout her time knowing Actium that he was a member of a Squad, learning that one of Kukui's other Pokemon, a Rowlet named Eule, had left the trainer's life for this Squad. And so she promises herself she will train herself, learn the strongest moves, and become something in Actium's honor. She therefore spends a lot of time in a fire type village, adopted by an Infernape with a Chimchar brother named Goofball until Goofball leaves and it's only her and the Infernape. Unfortunately, the Infernape is slaughtered by a Darkrai years later and Radon has to run away. She wasn't able to get away until an Emboar stopped to help, losing her life in the process thanks to the now darkened sky, which has lost its sun. 

Now a runaway, Radon decides the only thing to do is to join the Squad, impressing an old friend she recognizes when she single-handedly beats a Magnectrike and his sing-song friend group despite them having the power of mega evolution and superpowered song moves on their side. 

Eule recruits her and the two go to the Squad. She waits outside until he brings other Litten and fire types just like her as well as some other Pokémon. She Mets Barium and treats him with the same kindness. The two go on to save the sun, cementing their role as Starter Squad members as well as setting Nezcroma free. Now they are a fire type team with extra additional powers in Jab the Gliscor, Prism the dusk lycanroc, and Lunala. Eventually, Lunala and Jab leave the Squad to help Nezcroma with something and it's just Prism, Radon, Vesuvius, and Barium. 

Years later the arrival of Frisk and more dimensional traveling friends, Radon and her team are faced with an old foe none of them have faced, yet they take on the challenge with fierceness and kindness, defeating Kagis, killing him, and defeating Jabetu if only briefly. 

However, the battle wasn't without consequence. Eon, a strange Umbreon, died and many others were slaughtered. However, the strangest of them all, Prism completely disappeared into a strange wormhole with a strange black-and-white TV version of Rotom—Radon didn't know a TV version existed—with the last thing they all heard before her disappearance being "IT'S TV TIME!!" 

Radon is still searching for Prism with little to no luck, however can kindness still win for her? Maybe it already has....

Age: 23-25 human years (as of Stronger Monsters)

Main story: Missing Science

Fun Fact: Radon is named after an element on the periodic table 

Mate/Crush: Barium

Note: I might change some of Radon's history later, but I figured I give her some sort of backstory for now. I also realize that Radon and Eule were both starter choices in one of my books, but I am unsure how that can be...so I might have to retcon that. Also I just spoiled part of my plot for a different crossover that happens in the future. Let's just say big things in store for Prism. Big things indeed.