1. Harry Potter / Naruto
The gods of Naruto’s world reach out and pluck Naruto and his generations souls out of their bodies as The world is dying around them. They added Itachi’s Gen to the mix. They then drop them into Harry’s world with a message “Do better this time”. So now we have ninja with all their memories and skills without the chakra to feed it. They will have to learn how to use magic before they can use their skills properly
So now we have an Itachi hell bent on protecting his nephews and learning he was very much an idiot. A Shisui who gets to live. A Sasuke who finally understands the pressures of being the big brother, seeing as he has a tiny raven haired bundle toddling after him. Neji is released from his family obligations. Kakashi gets his ass handed to him by a pissed off McG because “sending your students into the world without proper instructions is a good way to get them killed Mister Hatake”
A Sakura who sees what she can be when not tide down with flights of fancies (read: Unhealthy obsessions). A Darco who learns the think for himself… if he threatens people about hurting his sunny sibling well I’ll just ignore it. And a Harry who gets the love, protection, guidance, and discipline his is needing. His big brother (Sasuke) and his uncle (Itachi) sees to that.
2. Harry Potter / X Men (sorta)
The phoenix entity attaches itself to a specific soul not blood. That soul being Jean Gray. A powerful sorcerous. Lilly Evans is that soul reborn. But unfortunately she isn’t what the Phoenix was hoping for. Instead of using the intelligence she was born with she dumbs herself down to fit in better. Instead of turning away from the people who see her as a trophy to win and horded she leans into it completely. Instead of seeing the man she married for the horrible piece of filth he is she ignores it. Instead of standing up for what she believes in she takes on her husbands ideals, wants, and desires as her own. Instead of staying in a safe secure location she follows her husband who bends his knee to an old man. Instead of sitting out of a war she didn’t need to be in she dove in head first following her husbands tail.
Through all of that the Phoenix had helped her out as much as possible. But seeing as every time it did the power influx left Lilly sick or near death it wasn’t often. On one memorable day Lily begged for a baby but because of the fighting and spell fire she was near barren. So the phoenix reached out infusing its power into Lilly and Jamas’s genetic contributions. Through the pregnancy the phoenix watched through Lilly’s eyes as she went into battle after battle putting her life and the baby’s at risk. The phoenix was pissed off and began to try and take control. Lilly’s core was still to immature to hold it completely so it was only a few hours a night it could do anything.
After the birth the phoenix bonded with its baby at night. Until that fateful day Jamas and Lilly was struck down and the phoenix was released. The entity had a list to get through and with Lilly gone that was one less. But Snape had added his name seeing as he had raced into a room with a bleeding crying infant looked at him and dismissed as unimportant as he cuddled a cooling body.
Seven days after Lilly’s death, four days after the body was finally buried the Pheonix finally walked the earth. Using the connection to its baby Phinix tracks the baby down. Watch out wixen world you have a living inferno standing behind you ready to strike.
3. Harry Potter / Percy Jackson
Harry Potter takes like at the young age of 24. As his formless soul slips into the Netherworld death meets him. Gathers him and takes him to a meeting of the strangest verity because standing there tearing the gods themselves a new one is his mother. She is demanding they give her son what they denied him. That he deserves a boon for every drop of blood, every ounce of pain, every betrayal, every lost opportunity they caused him to suffer. That he had done what they wanted.
Harry finds out he is the grandson of Hecate herself. It is also found out that Ares is the one who set him up and that particular god is punished by Kosmos himself. One of the laws known in Olympus is No god shall ever target another regardless of origin.
Lilly gets her way of course. Lilly uses two of Harry’s boons to give him a better life. No magic whether malicious or not could settle into his body without his knowledge and allowing it. No danger would find him unless Harry goes looking for it. And so Harry is returned but not as he was. A new life was given and of course he asked for a boon before his rebirth. He wanted Draco as his soulmate. The gods drew up a contract that Draco must sign of his own free will. Harry ends up leading Draco to the truth of his family. And ultimately that Harry has been protecting him from A LOT in the process.
That Lucius is using him as a stepping stone to further his own agenda. That Narcissia could have gotten herself free of that horror called Malfoy manor had she wanted to. She controlled the wards whilst Lucius was unable. That both Malfoy parents could have assisted Draco in his tasks or taken them on themselves. Instead they pushed it onto a child’s shoulder all the while whining that they would die if Draco didn’t complete them.