Inspired by, but not a complete answer to, Quatermass' "NEET Freaks"-challenge. No true summary yet. FemHarry!

(Harry/Tiamat!) An obsession with changing his own history plunges rogue Unspeakable Harry Potter deep into the past, and into the Reverse Side of the World. There, he befriends a Beast of Calamity...and by doing so, sets in motion a change in events to come. But can Harry and Tiamat overcome their pasts to save the world? Or will they regress back into their dangerous obsessions?

When Arturia Potter realizes that no one will ever truly help her survive the upcoming war after her godfather's death she chooses to use a rather odd ritual that she found in her second year to summon someone to help her, only it doesn't work out exactly how its supposed too. Now with a Half Incubus and quite fully alive servant how will the young witch deal with the consequences?

(Harry/Serenity!) The escape from the graveyard at Little Hangleton goes awry, and Harry ends up in the Camelot Singularity, where he makes the acquaintance of Hassan of Serenity. Now, some time later, Harry, now a member of Chaldea, is able to go back home. But there's a problem: a Pseudo-Singularity is affecting his world, Servants are battling it out, and a dark plot awaits...