"Disclaimer, this game might be a persona clone, but it's all due to the fact that Rooster Teeth might pay Atlus for a unique take on Rwby by mixing a genre between rpg and social simulator just like the persona series with a Rwby twist, also, this game is a work of fiction, specific characters and settings throughout this story, especially the game's depiction of New York City, are purely coincidental."
In the very beginning, Monty Oum died caused by an allergic reaction back on earth, he was reincarnated into someone else in another world called Remnant in the true issekai fashion, and that's how Dante "Cross" Rose(his full name) came to be.
Cross was a cosmic plaything until now, who was born three years before his sister Ruby and have no semblance since birth until then.
Ever since he was born, his old home got attacked and destroyed by the grimm and was sent by his mother, Summer Rose, from Vale to Atlas, Moses style, and was raised by the continent's carefree fisherman named Olbric.
At age 13, he attended Atlas academy since the birth of his sister, Ruby Rose, as he wished to fufill his own destiny to become the huntsman and eventually to become the people's protector even if he doesn't have a semblance, he has a very special spirit that gives him the potential to unlock his own, as he not only studied and trained here to improve his intelligence and strength, but also became a member of team WICK (Winter, Irina, Cross, and Krom).
Three years later during summer, just before he became a senior, he witnessed those poor fauni working without taking any breaks.
Cross know what he has to do, he rushed through the market to buy some food and drinks and went back to help, "even if it means breaking Jaques' rules due to his bravery and kindness" (this scene is a literal "screw-the-rules,-I'm-doing-what's-right!" Trope) as he took one's place for another to take a break. Then he gets caught helping the faunus, as Jacques ordered the arrest on him. Not only did he get expelled from atlas, but also got arrested for breaking Jaques' rules, resulting to be kicked out of the team and broke Winter's heart. Until one day, Qrow came to the rescue and introduce himself as his uncle while breaking him out. Cross had never felt happier with his uncle, and it was a daring escape for himself, as they snuck into Winter's airship and flew to beacon at Vale, as a result, Cross was branded as fugitive and traitor to the country. Ozpin then welcomes Cross while analyzing his strengths and weaknesses and then decides to break the division number rule by making him a manager of team RWBY(if you add Cross to the team, then it's CRWBY) because if the leader can't decide what to do, then he steps in to shine the light of the team with his own knowledge and skills, as he started his new life at beacon with his two sisters and made new friends along the way.
Cross walked with Ozpin later to the hidden relic vault at beacon, and when Cross accidentally opened the vault's chamber, Oz was stunned with amazement as if even if he wasn't the maden, he can still open the vault anyway(this tells Ozpin that something is different from him and tries to understand why the relics chose Cross). Two years have passed that night, the grimm and the white fang came and destroyed everything at beacon. Grief and tragedy has followed him since birth, Cross makes his desperate struggle as he picks up one of Penny's swords to help Qrow, Glynnda, CFVY and general Ironwood to fight through the horde to reach to beacon academy and that's when he met Tortchwhick as a tutorial boss fight in the form of the atlesian paladin while neo was distracted by team CFVY, and he ends up working together with his uncle, assistant principal, Wiess and the general. He then managed to defeat and change Roman's heart at the same time and killed his demonic grimm-self with this mysterious power for the very first time, however, his redemption is equal to death, as he sacrifice himself to buy Cross and others time to achieve thier destiny. He then found his sister Ruby, as he carries her to safety outside of beacon until he's attacked by Adam out of nowhere. Cross is only armed with Penny's sword and then gets overwhelmed and stabbed through the chest, until he used his silver eyes for the first time as the last resort against that masked faunus, Adam was blown away by his sheer wave of light causing a serious injury on him by damaging his limbs, then Cross was suddenly thrown into the coma right after he came on top against his opponent.
During his coma, Cross met the deity of light himself, revealing as the real father to him, as he was told by his deity father that this mysterious atonement power is revealed to be a gift from himself rather than the semblance and he'll unlock his semblance when he came back from the coma(it is also revealed that the reason why the relics chose him is because of the special gift he have inside his spirit which foreshadowes that his status will be a messiah), through temporary exchange of his memories.
Cross accepted the exchange, as he came back from the coma three days later and became a demigod. Everyone including Ruby asks how he feels, as he completely forgot about who he was. She explains how he got here at home that it was Russell "Virgil" Ironwood who carried him to safety. Then half of his memories came back to him,(which is part of his semblance) as he got to know his sister as his first person in contact, until thier house was attacked by one of the ursa grimm, as cross picks up Qrow's weapon to fend it off, this is when cross fully utilizes his semblance for the first time, as he mimics Ruby's speed to take advantage against the ursa while the second half of his semblance fully recovered his memories. Outside the isle of patch, just three days after beacon fell, Russel talks to his friendly rival, Cross that he was a little too late to stop the apocalypse that turned the world's surface inside out. As soon as the world transforms, killing 70% of everyone, Cross and the rest of the 30% were transported safely to another planet called Earth! That's when he realizes what's become of the world of remnant, as he remembered through his memories to the point he notices that the world was divided, and is now filled with corruption and prejudice, as he's like saying in his mind "this world is twisted and it has got to change!"
Now he's a different person, as he got into the "zero-to-hero" territory by becoming remnant's messiah and went on the quest to avenge his mother against the grimm while he atones and unite the world against Salem and purify the four relics with the divine power to change people's hearts with the style of cutting down thier inner-grimm with his sword he created for himself. (He also became the manager of both teams RWBY and JNPR "because Pyrrha came back to life, only as a hollow bunny mascot costume like Teddie") while also living thier daily normal lives as highschool students at the place called New York City on planet Earth! Cross is a combination of Jesus Christ of the bible, Yu Narukami of persona 4, Prince charming of the princess - involved fairy tales and Dante Alighieri of the divine comedy.
The story of the game is inspired by a mix of both fables and Christian mythology and takes on the central themes of forgiveness, salvation and redemption along with the importance and unpredictability of family and friendship(tv tropes:"Can humanity's salvation and redemption be attainable?), as he use his gift to lead each rwby villains astray against her ambitions to help unite and save the world in order to prevent Salem from using the relics once again on earth and restore the world of remnant to it's rightful place, not just from her, but also from the god of destruction himself in order to reverse the damage inflicted on the world of remnant and free it from the chains of bias and malice.