The Devil Herself
B62/100Web serial by 13 Sparks
Ellen goes from being a flight attendant to being mistaken for the devil herself. It all starts locked in a dungeon — a place to meet the best sorts of people — where she saves the life of a psycho cultivator. She never figures out if he's a hero or a villain, but he's certainly good at killing people. He takes a shine to her and teaches her how to cultivate to defend herself. But he's busy trying to kill his cousins, so Ellen's cultivation takes some unexpected turns: she becomes a pyromaniac, starts abusing geometry, and eventually steals some hellfire because it's not hot enough until you melt the walls. A slow-burn romance between a workaholic and someone dense as a brick, with a good helping of magic, violence, and sarcasm along the way.