Here a Arc-V idea

What if Leo Akaba met a relative of Zarc ? The relative made a deal with him, the deal is if he can find a way to get the darkness out of Zarc, he\she can bring Ray back without sacrificing her's fragragments because it was the peoples fault for wanting him to fight more savagely, the mystery person later revealed to be Zarc's Aunt who blame The peoples who made her nephew into that demon. She made a plan not only to bring Zarc back but keeping his fragments alive as well, her plan is when Zarc was revived along with his fragments, she will take them to an another world in a secret place where they will be living. (I will let you decide the rest) P.S. I also hope that Rin, Ruri and Serena, Yuzu will be there along with Ray.

Here a another idea

What if a stranger made some sort of deal with Leo Akaba that he/she can bring Ray Akaba back with her fragments bracelets without the girls but only have some sort of DNA (It can be your choice of what type of DNA you want) the stranger want him to bring Zarc back. Leo completely refuse but the stranger got something to take out the darkness inside of Zarc, Leo Still mad listen to what the stranger is saying, the stranger continue by saying he/she got something to make the darkness inside of Zarc disappear. Leo agreed but ask why he/she want Zarc back the stranger reveal to be someone from an another world. Someone sent him/she to bring Zarc and his fragments to their world for something, Leo shake the stranger hand and begin the plan.

YU-GI-OH VRAINS Ideas

What if Queen was Yusaku's mother ? She has been searching for him for years after he was taken one night. After some years past she got a job at SOL Technologies, as the queen was moving up the ranks she learned about the Hanoi Project, she saw some pictures of kids that were chosen for it, she then saw a picture of her son Yusaku. Queen was mad as she can be then she started to work on a plan on finding her son, with the help from SOL Technologies and a few people She trusted. When she heard about Akira Zaizen's little sister Skye about one of her classmates whose name is also Yusaku, Queen has someone to take a picture of him, when that person returns with the picture Queen eyes widen and she has someone analyse the dates and picture of Playmaker. After a week has passed it was finished and when Queen saw it she knew that Playmaker is her missing son. She then started to work on a plan to get him back.

Another Ideas this one can be from season 2 episode 13 if you want

What if the Knights of Hanoi made a plan on having Playmaker on their side by brainwashing him, Varis the leader of the Knights of Hanoi whose real name is Ryoken Kogami, soon he and Spectre along with the other members try to find a way to kidnap Yusaku. After finding where he lives, one of them went in and put something that will make Yusaku stay asleep, when he is brought to the hideout one of the knights put him on a machine or bed. Dr. Genome and Ryoken, someone else (can be your choice of who you pick) begin to talk on how to make Yusaku join them that act on his free will. When they decided, they start the process, ( I will you decide the rest)

Will Yusaku's friends find him and save him ?

Another Arc-V

What if Zarc's parents still remember everything about the original Dimension and what happens to their son who becomes a monster because of the people, when they were transported to the fusion dimensions they saw Yuri who had the same face as their son, but when they looked at his memories he didn't have any as Zarc and realised that Ray and Zarc were split into four people. After some time passed they met Leo Akaba and they talked him to see if he remembers Zarc and his daughter Ray and he does, Zarc's father blames him for what happened to their son. That he should have done something so that their son wouldn't have turn into a monster, because of the people who wanted him to be what they wanted him to be for them. So after talking for a while they each made a deal for Zarc's parents if they and Leo find a way to get the darkness out him and his fragments they take them to another world. (It can be your choice of what it is, it can be Vrains or seven, Go Rush) for Leo Akaba deal they help to get Ray back, but unknown to Leo Akaba, Zarc's parents were planning on making a clone of Ray instead of reviving her. They also found two scientists who wanted to help, (P.S. I was thinking that when Zarc is revived his fragments was turn into babies and they was taken along with Zarc and his parents, also for the bracelet girls they actually taken their bracelets and a blood sample for the clone) I will let you decide the rest.

Here a ZEXAL

What if Number 96 kidnap Yuma and slowly start to brainwash him to be his servant, or have false memories of Astral and his life ? Will Yuma be saved before it's too late ?

Another YU-GI-OH Vrains ideas

What if Queen and the Higher-ups have Kenneth Drayden aka the Shepherd, to find out Playmaker identity ? when they found his identity they have someone to make a serum to turn Playmaker into a child. They made a plan about turning Playmaker into a child to re-raise him, they have Queen who did research on child raising and hire a nanny to help once in a while. When they find out where he lives they have Shepherd go to his apartment and bring him to them, when Shepherd return with the unconscious Yusaku he was then given to someone who was going to prepare him, when they give him the serum it was a success but learn he still have his mind and memories, when they did tests on him, so they made something that will make him forget everything bit by bit. (I will you decide the rest ) will Yusaku friends and ai find him and restore him to his rightful age and memories ? Will Queen slowly develop feelings for Yusaku as a mother ?