HP: Kill the Dark Lord and Become the Dark Lord!

【Complete + Harry Potter’s Marauders Era + Fantastic Beasts + Next Generation + Transmigrated from the Primordial World | Pairing: Severus Snape | OOC warning! Loads of original worldbuilding!】 Dongfang Yilan accidentally falls into Hogwarts and meets a sharp-tongued bat with a soft heart. The road home is always difficult, but even three billion years aren’t enough to defeat Dongfang Yilan. Time travel keeps going wrong, though. The first time, she meets Snape while he’s eavesdropping. The second time, she loses her memory and attends school with him. Without her memories, Dongfang Yilan eagerly absorbs knowledge and, along the way, saves young Severus. The third time, she returns to Dumbledore’s youth. Ariana must not die. The fourth time, Hogwarts a thousand years ago is truly breathtaking, though she accidentally brings Snape along. At last, that adorable little bat has grown up. Dongfang Yilan is pinned against the wall as he asks, “So this is the truth behind your memory loss and disappearance?” The Dark Lord has returned. How could she let Severus suffer? She’ll take him down and return to the Primordial World! Wait, is something wrong? Is this really the same world as before?