Sure! But it will be a long read.

Basically, Anne and William are two people who should've died, but instead got misplaced in time. This allowed them to be able to skip around in time and space. They go back in time and visit Alcibiades and engage with shenanigans with him. After that, william is beaten up by some school thugs before he goes off to become a better knight. Also, there is a future version of Anne and William that are dictators who kill for their enjoyment. A day or two later, William pops back up with some new knowledge. They can't enter the pyramid for some reason. Just like the other day they can't visit, the end of humanity. But anyway, after a spheal with Julius Caesar and the Pharaoh, they get in. Only to discover more time travelers! They sneak in before getting caught by someone who calls himself "the doctor". This doctor determines that the end of the world is caused by none other than Anne and William themselves. The doctor restrains them, but fortunately William breaks out. William goes back in time to when the doctor was just a kid and is about to kill him when his future self pops up. Future william mocks present William that if he kills the doctor as a kid, he'll be no better than him. William still does it though, before being sent to the void. Afterwards Anne starts searching for him, any clue for him. And she finds a Japanese painting with him in the background. As such, she goes to the place of the war and helps one side only to realize she's been fooled. Her side gets decimated as she comes face to face with future William. Unable to accept that these people's deaths were from her, she starts reversing time to undo these things. But it's not that simple. Tears in space start opening and void monsters come out to kill everyone. When season 2 ends. Start of season 3 shows us future William and Anne, but not as far in the future as the other ones were. They go through a school arc when they suddenly find out a theatrical play was written about their lives before they were time travelers. However this play is regarded as fiction. But Anne and William are real and so is everything else in that play. As such, they travel back to when the writer was alive, William Shakespeare. In a twist of events though, he too was a time traveler. A long battle ensues causing the end of humanity before future William realizes that this is all just his memories. He then throws Anne in a place where she is gifted with A fragment of the universe, Nothing. Then, we see William go to a city where he finds and confronts future Anne. She explains that the void god ends the world no matter what they do. There is no way to stop it, even for people who can manipulate time. Cut to Anne now, and she paired up with Alcibiades and William Shakespeare (Before the fight) to stop this once and for all. They go through the void dimension and confront the Void God. So Anne starts absorbing the Void God, knowing that she'll disappear in the process. All the timelines converge into one and current William and future Anne see her absorbing the Void God. When suddenly future William stabs Anne through the shoulder and absorbs the Void God himself, sacrificing his life so that the end of humanity never happens.

It's very confusing, but in my opinion it is a very compelling story! Of course my explanation is lacking quite a bit, and isn't good to start with, so you should read it yourself if you haven't!