Secret formula that make you mom, wife o girl fight like professioanal killer or kickboxer, she become strong and very skilled, and by this, she take it and fight with other women, and a qiuck recovery is allowed, but when formula run out of time its very sad un the end of battle
For example two moms take it and start to fight brutal, like in the movie with scott adkins or mortal kombat, and when formula run out, one of them taking bad....
I commissioned a writer - Luffy316 - to write a series of stories featuring something very similar. A skinny little blonde gets a formula that makes her a badass fighter and she gets revenge on all the hot girls who tormented her.