Radiant Hope was merged with the Umrum DNA when a bucket of ice, with mixed with Rabia’s DNA, was dumped on her to amplify her dark magic powers. Her Umbrum blood was supposed to activate around the time of Siege of the Crystal Empire, but it did not happen. However, months later, she encountered the spirit of an evil queen, whom’s body was trapped in a manchineel tree. Claiming to be Sombra’s mother, she slowly activated Hope’s Umbrum blood, and brain washed her into unleashing her full dark side. This was around the Sombra and Hope finally managed to get the last peace of Princess Amore back, but instead only bringing her back to life, Hope then turns the shard into dust, tricking Sombra into thinking it just happened, and causing a blizzard to appear before her transformation was complete, until she could find away to hallucinate her image.
After she was able to find away to do so, she decided to go search for her childhood friend, hoping he did not notice the her transformation, and that she was the one who destroyed the final piece of Princess Amore, eventually running into Spike the Dragon. He claimed that he and the CMC ran into Sombra in the outskirts of the Crystal Empire, and while the CMC take him to Ponyvile to help him make new, Spike would go searching for Hope. So when asked if she knew Sombra, she told her she did and asked if Sombra mentioned anything suspicious about the blizzard. Spike admitted he didn’t and after a brief conversation, took her to Ponyvil, where they found Sombra being confronted by the citizens as they started throwing stuff at him while he was restrain to a post, calling him a monster and freak. Luckily, Hope interferes and tries to convince everpony that newly named “Sombra Blankflank” was not the monster he once was, and that he was just misunderstood. On and on from telling them that it was okay to be different to shielding him, and what seemed like two hours, she was finally able to do so.
Hope was able to keep her secrets for a while, but unfortunately the longer she held the Umbrum blood back, the more difficult it was to control, as if it was developing its own personality; One day when she was walking on her way to visit Sombra’s new apartment, when she heard a sinister sounding voice calling “Hope… “. As Hope turned around, she saw no creature there, but the voice continued calling her as if it was attached to the back of her head. Hope tried to run from it, but the voice continued to fallow, until she tripped and fell face first, and was left unconscious. She woke up seeing a huge umbrum like ram standing right in front of her. It was Grogar the Umbrum king, and claimed to be Sombra’s father. Not only did he confirm that the unicorn queen, whom’s body was trapped in a tree but’s soul was trapped in purgatory, was indeed Sombra’s mother, but he also, using his powers to look into her memories, reminded her of the umbrum blood within her. He also showed a memory of where she receives a letter from the two alicorn sisters, but Sombra did not receive an approval of any of the alicorns, then Grogar showed her another memory of where Sombra shatters Princess Amore and Hope runs to find and warn the alicorns. Afterwards he showed her another memory of where King Sombra finds a way to kill the alicorn king, the pony he admired most, the pony that gave him more hope, and one of the few things that kept Sombra’s mind off of what he saw inside the Crystal Heart. Grogar then flashed forward to a new memory where Radiant Hope finds a letter showing the alicorn king’s approval of Sombra becoming a student of the two sisters, as Celestia claimed that Sombra would have been a disaster to her all pure breed pony school. Reminded of why and how she really left with regret, she felt enraged as Grogar pointed out that some that Sombra’s fate could have been avoided if it were not for that one discrimination.
Shortly after Hope woke up, and thinking it was a dream, she tried to dispose of what she saw while unconscious, but somehow the anger was still there; When she got to Sombra’s, he greeted her as she noticed a nearly complete statue of Princess Amore, with only a small chunk missing, standing in the living room. With it was Princess Celestia standing right next to it. Sombra revealed that Celestia had restored the last peace of Princess Amore, and that they could finally bring her back. At that moment, Hope then asked Celestia if Sombra could join her academy and if he was fit for it. After Celestia denied, Hope then pointed out that she was lying, shocking Sombra, who Hope never told. Celestia then confessed, claiming she was wrong, but still refused to let him in stating that “It would be damaging to my reputation to have the evil King Sombra at my school, and now that he knows I discriminated him a thousand years ago, he’ll never join.” With furry and rage, Hope let out a devilish scream as strong force pushes Celestia and Amore to wall, while Sombra watched in horror at what she had become. Using her magic, Hope lifted Amore up and turned her into ash claiming that was Sombra should have done instead of sparing her life. In horror, Sombra witnessed the closest thing he ever had to a sister had become umbrum. “Hope, w- what’s happening to you? Do you have any idea what you’ve become?” Hope sinisterly smiled, as she levitated herself while using her magic to steal the Alicorn Amulet from Celestia’s satchel pack, which she brought to help her restore the shard, and a cloak from Sombra’s closet. As they come on her, she said in a feminine, demonic, yet sinister sounding voice “ Don’t you see Sombra? I have become what you once were. I have become the umbrum hybrid I was meant to be when I brought you back to life. I tried to hide this from you Sombra, I now realize that the memories it would have brought you back to reality, where we were put in a spot where we pretend that it’s the same as every creature else’s. I met your mother, who activated my power, and your father, who reminded me of why I felt guilty for turning you in. I realize now where I’m ment to be… “ Her cutiemark then started to change colors as she spoke. * “I am your backup. I am the umbrums’ next captain. I am the duchess.” Sombra then paused for a moment, staring at Hope, noticing that her cutiemark was now a grey medical symbol with green snakes. Celestia then tried to attack, using the alicorn amulet Hope then shot a beam at her, weakening her.
The two then fought, Sombra and Hope, and their battle was fierce, from shooting beams to going through house hold items, to even going through walls, eventually taking the battle outside. As fight progressed, Sombra repeatedly tried to convince Hope that she didn’t have to be this way, and that there was still hope for the world as things could change peacefully for every creature. Unfortunately, Duchess Hope kept failing to see it that way. The brawl made it’s way and started to tare apart Ponyville. As Twilight noticed Ponyville being destroyed, she ran out of her school alerting the others, in order to stop the fight. With the help of Starlight and Spike, the Mane 6 were able to find away to restrain Hope, using special restrains from Sombra’s ruined apartment, the same one he used to capture and execute the original alicorn with. She couldn’t move, she could not use magic, all Hope could do was growl, roar, and hiss as the fear, anger, and everything thought bad, (including memories), were brought by them.
Hope was sent to a mental institution, where it was hoped that she could be treated. Luckily, she was able to regain some sanity, and acted less scary, even Sombra was seemingly able to help her out on the road to goodness, just like she did for him, but deep down, she knows what was wrong with the world. She knows that until discrimination stops, there will always be consequences. That there will be some creature, peaceful or violent, who speak out against it, whether they are good or evil. No creature can truly be the same, and if others do not encourage them to embrace it, they encourage them to shame it and put them where their kind is believed to belong, believing that it is basically the same thing, when in reality it is actually not. She knows they can use fear ether as a reason why they don’t speak, or why they use it to speak. Her best friend was discriminated, and she just showed them the consequences.