Gem AU's

Saiki k gem au

(Warning spoilers for the Steven universe tv show!)
Steven universe rebellion explained: so in the show there's 4 diamonds who rule everything. The youngest one, pink diamond is gifted earth to colonized. When a planet is colonized the diamonds use all recourses on the planet to make more of their species, which in turn destroys a planet. Pink diamond falls in love with the planet and tries to convince her family not to destroy the planet. When that fails, she creates a rebellion (which resulted in a war that killed a lot of gems), in order to scare her family off. When that failed she faked her death thinking that would scare them off and get rid of her responsibilities, which resulted in the exact opposite. The diamond became so enraged that they used their powers to transform all rebels into monster, expect for a few pink diamond, who is now know a rose quartz, was able to save. And that's how the war ended, and where this AU will begin from.
Also to be notes, gems have a special ability. When they get too injured, they poof, which means their physical forms stay in the gem stone on their body. So if you damage a gem enough, the gem will become a gem stone for a long time before being reformed with a new look.
So for the Saiki k gem AU, the rebellion Kinda failed. The Crytsal gems were all corrupted into animalistic creatures except for a hand full of gems like in the show. Except after the Pearl isn't saved in this AU. When she's transformed into a monster, rose loses her cool and trans forms into pink diamond infront of everyone, which breaks apart the crystal gems and ends with rose being poofed and locked away for a long time.
From there the gems live through life like normal, except they have to hunt down what once were their friends, and either poof+lock them away for their own safety, or if they dream they are to far gone, the corrupt are killed.
Years pass of this, which as you can guess results in a lot of death, leaving 3 crystal gems left in the early 2000, when a certain pink one falls in love with a human man. She leaves her job and moves into a tiny house in Japan with her husband. One thing leads to another and they're soon expecting a baby. Yet, before the gem has her son, her husband is killed in a car crash which leaves her a wreck leaving her husband's sister, Kurumi Saiki and her husband Kuniharu Saiki to look after her.
They try their hardest, but nothing helps her much. That is until she grabs on Kurumi's hand one day and makes her promise that if something was to happen to her they would look after her baby. This of course terrifies Kurumi to think of, but she agrees to do it.
The day of Saiki's brith eventually comes, but his mother dies having him. It's almost as if she knew she just didn't want to live anymore. When she dies her gemstone is given to her son, which is on his left shoulder. So this makes Saiki part alien, which in this AU gives him a lot of powers.
Yet, in this AU, his brother is nicer to him because before Saiki was born he didn't have any friends. So when Saiki k came into his life, his brother finally had a friend. As for the rival kart, Saiki didn't show any of his powers until he was four, so it is there slightly but not to such a high extent. As for the whole adoption thing, Saiki has no idea he was adopted. All he knows is that he is part gem and can do a billion things because of it.
Now he goes to the high school and everything is the same as it is in the show. That is before what's left of the corruptions show up in Japan. This means in the AU Saiki has to keep people from finding out he's an alien and battle monstrous creates that share some of the same powers as him in order to keep the world safe.