After the First Task, Dumbledore is removed from his position as Headmaster of Hogwarts due to an examination by a DMLE-approved Mind Healer finding him unfit to lead the school. Meanwhile, Harry does his best to understand his conflicting feelings towards Rin's death, with the support of Homura, the two bonding over the process, and the Fire Sekirei finally accepting their relationship.
Harry does not attend the Yule Ball, as it does not count as a Task, instead attending a ball at the Shiba mansion, to expand his network and influence on Japanese Soil. He also plans to use the opportunity to push forwards the investigation on Rin's death, suspecting foul play by one the wizards or witches now employed in MBI's magic branch. He even brings his sister, after she got their parents' agreement, to introduce her to the wonders of Magical Japan. He also offers to take his brother, but Sirius declines, as he is more comfortable spending Christmas with the Potter family.
The Second Task is easy to prepare to, as Lily, hoping to help Harry, passed to Ivy what she heard from Moody, allowing him to prepare efficiently. Of course, when the Task begins and he discovers that what was taken from him was his sister, he is none too happy and quickly moves to rescue her.
In the Dark Lake, he also rescues Gabrielle Delacour, as thanks to Homura, he is aware that Veela and cold water do not mix, which ends with him having to fight the Merpeople, who are unusually aggressive, refusing to allow him to rescue the girl. Eventually, he has to use his Norito state to escape, as while extremely powerful, he is unused to fight underwater.
After seeing his true power, Magical Britain starts to ostracize him, as while he has plenty of support, most see his power, willingness to do whatever it takes to reach his objectives, and clear disdain of their customs and culture, as the sign of a budding Dark Lord. This is only reinforced by Lucius Malfoy and Umbridge, who use everything in their power to make Harry's life miserable.
While Umbridge is dealt with easily thanks to his status as a Lord and bringing the matter before the Wizengamot, Lucius was careful to not leave too much traces of his involvement, and only ends up fined a significant amount of money. Still, that is enough to gather even more resentment from the hardest Blood-Purists, who start to work together to find a way to get rid of him.
Eventually, the Third Task arrives, with little to no progress made in regards to who brainwashed Rin, and with a rather large portion of the magical population clearly eager to see Harry and his Sekirei leave.
The Task is complete easily, as Harry has absolutely no qualms demolishing the hedges marking the labyrinth, and, before taking the cup, successfully determines that it is a Portkey. Having a good idea about what to expect, he grabs it and ends in the graveyard of Little Hangleton, where Barty Crouch Junior and Voldemort are waiting. He kills the first, tells the second his Horcruxes have all been destroyed (Nagini was dealt with the moment he sensed the snake) and he kills Voldemort.
After coming back, Harry prepares to leave, only to feel Karasuba suddenly vanish from Hogwarts and reappear in Azkaban. Despite immediately using his Norito and moving at speeds beyond anything he should be capable of, he arrives only in time to see Karasuba overwhelmed by over a hundred Dementors, and her soul sucked out. The feeling through the bond he shares with her is enough to send him into a complete rampage, and he utterly annihilates the entire Dementor population of Azkaban, as well as the island itself, his Sekirei's body safe in a bubble of pure magic.
Fortunately, Karasuba's body being alive and the Dementor who ate her soul dead, said soul is freed and returns to the body, the Black Sekirei returning to life, albeit so completely shaken that she displays none of her usual personality and clings to Harry like a limpet.
Now that she is safe, Harry returns to Hogwarts with Karasuba, ready to tear the castle apart to find who was responsible for what happened. As he arrives, he is trapped inside a trap negating his powers, and he is taken into custody by the Unspeakables. The Ministry has already issued a warrant for his arrest, supported by Lucius Malfoy and many of the Purebloods unhappy with Harry's actions, and hoping that the Unspeakables will find a way to replicate his powers that they will share with them. He orders his Sekirei not to intervene as the ward used may be used on them as well, and while he might only get experimented on, he is well aware of what would happen to three beautiful females if they were caught, not to mention he wants someone to help Karasuba overcome the trauma of her death-like experience.
And he knows full well that it is only a matter of time before they may intervene and rescue him.
And indeed, one week of captivity later, the British Ministry is attacked by Harry's Sekirei, who decimate all those who oppose them and rescue their Ashikabi, before bidding a hasty retreat to Japan, the time to lick their wounds.
Once they are back, Harry use the opportunity of being effectively confined to the island nation to investigate what happened to Rin himself, gathering information from the involved teams, and overseeing a complete inspection of MBI's video footage.
While nothing obvious is shown on video, a few helpful comments here and there from those who knew Rin allow him to eventually discover that Rin was investigating a possible secret MBI facility, rumored to be the host of experiments destined to replicate him, and to create humans with Sekirei powers.
A visit to the facility proves that not only does it exist, but that the experiments were successful, as a gleeful Minaka demonstrate his new "Godly powers", revealing that he was the one behind Rin's brainwashing, given that she was hampering his plans in creating a new race of Gods. The man admits to have sent her after Harry as a form of test, stating that a God should not concern himself with the lives of those lower than he, and congratulating him on passing the test.
Harry is not amused, and neither are his Sekirei.
An all-out battle ensues, where Harry and his Sekirei have to fight for their lives, Minaka's experiments having created many successful hybrids, and while more powerful and more in control of their abilities, their enemies make up for it in sheer numbers.
Eventually Harry manages to kill Minaka, but the events of the last months have left him bitter and resentful of the Human race. As such, he takes control of the Sekirei ship, and broadcast a nationwide message telling those who have Sekirei and who desire to live a life free of Human rules and strife to join him in a journey to the Sekirei homeworld.
While few join him, Harry then broadcasts another message, this time worldwide, divulging the existence of magic and the presence of magic societies on Earth, before listing a few examples of casual violation of Human Rights and of the general mentality of magic users, before stating that those with magic who wish to emigrate to another world, free of the Pureblood dogma, are welcome to join as well.
Any attempts to seize the ship are violently rebuffed, and Harry ends up with a little over two hundred people, among them the Potters, willing to join him.
Just as they leave, Harry watches news that the Queen of England had ordered the forced handling of the British Magical Society, with the death penalty reinstated for those whose crimes are too great to allow to roam free.
Keep in mind that this an abridged version of what I had planned, and that it may have been changed to fit new ideas as they came.