(Now this is just an idea and here is a brain dump:)

In the world of RWBY, there exists a young man named Stavros Nikkos, who reincarnated from the real world after suffering a heart attack at the young age of 17. He is reborn with a birthmark that resembles a cross, his name chosen by his father in hopes of giving him the ability to endure hardships and carry the burdens of others. Stavros's father, Alexander Nikkos, is a renowned huntsman with an incredible Semblance: he can control the iron in his blood to increase his speed, strength, and durability.

Despite his father's legacy and his sister's training to become a huntsman, Stavros doesn't care about becoming one himself. He only trained in some basic sword skills and a lot of working out to keep his body toned. However, thanks to Pyrrha Nikkos, who Ozpin needed her in beacon Stavros is given a shot at initiation.

Stavros cycles between Team JNPR and Team RWBY during his four-year curriculum, which requires him to have a team of four huntsman trainees.

(as you see Stavros is going to be weak as fuck in the beginning and its only his fault he could have trained with his father or even with his sister but he never wanted as he thought it was time-consuming and he promised himself to live life to fullest and not waste his second chance now you see this is kind of the opposite of jaune arc and I like that it will give them something to bond on as I plan of making jaune play a major role in the story. now I'm not going to say the whole plot but I'll give an idea)

on the year Stavros was born eight giant crystals given the name the mother crystals materialized on remnant (ofc no one knows this small info or that its smth important) scientist believed these are giant Dust crystals. since they exhibit similar energy readings but on titanic scale compared to normal dust crystals however, they can't actually know due to it being indestructible and can't be hurt by anything so for now anything they say is purely theoretical till something happened after 8 and half years (smth happened to Stavros at that time) from appearing the dust crystals shattered and from inside them emerged 8 massive beings which were given the moniker eikons. While they are unique in terms of physical appearance, Eikons share some similarities in that they are massive in size, towering over humans. Eikons' bodies are theorized to be composed of dust, since they can heal their bodies when damaged by absorbing dust from the environment, even being able to regenerate lost limbs in a matter of seconds and because of that they are indestructible as after a concentrated bombardment of 20 days the earth eikon who is known as titan was destroyed completely but regenerated his body in a matter of hours and wiped the whole fleet They have been theorized to transform into even more powerful forms by absorbing massive amounts of concentrated dust but till now it didn't happen so they aren't sure. An Eikon embodies one of the eight elements of the realm: fire, ice, lightning, earth, light, darkness, water, or wind. which are all dust elements or a combination of them. now surprisingly eikons are pretty docile and only attacks if attacked be it Grimm it left the world on edge as the eikons looked to be waiting for something or someone.

(As you can tell this a crossover but a massive one just some stuff I'm not gonna get the whole world of ff16 and put it in rwby. so, if you can offer advice I would be happy to hear or even suggestions for the story)