Konosuba Megumin the New Demon King

This Fanfic may contain spoilers of the final volume, I don't own konosuba all credits goes to Natsume Akatsuki
This took place on the end of konosuba in which Kazuma and his part took down the demon king ,he was separated from megumin and darkness before dealing the final blow, he died after he took out the Demon King and he went to heaven with Aqua and received his reward wish he asked for his wish to go back to konosuba world with Aqua but he need to fix the trouble he made when he brought Aqua to konosuba, Darkness and Megumin were busy looking for him after they were separated (not knowing Kazuma took down the DK, while still searching for him they stayed in Alcanretia), they decided to retreat after they never saw kazuma and asked others for help, Kazuma was searched everywhere but never seen,in the world's largest dungeon they found the body of the demon king and Megumin went on mental breakdown while Darkness while still shocked, the next day megumin went crazy trying to figure out were kazuma is and met Seresdina, now a former general of the DK, and learned how to become a new Demon King, she's told that there are some spells that were hidden in the Demon King Castle that can turn her into a demon king that she may bring back Kazuma, not knowing it was a trick (she can turn into a Demon King but she can't control her actions afterwards), she went to the Castle with Yunyun, Darkness and Mitsurugi to search for the spell(they didn't know what she's up to), she turned herself into a demon and went on rampage wounding both Yunyun and Darkness and cutting off Mitsurugi's right arm and flew into the Crimson Demon Village and killed many of her friends and acquaintances, she went calm for a short period when she saw komekko being carried by her friends but she still attacks them but was blocked by her parents, which perished in her hands