Can be anything from any source, movies, books, comics, video games, manga, anime etc.
Pic related is mine, the dragonslayer from berserk. I like it because it’s simple. It’s just a big fucking sword, no fancy bells and whistles like enchantments or spells.
Second runner-up is sting from lord of the rings, I like that it glows blue when orcs are around and it can be used in the dark as a light source.
Maces generally were used against armored opponents in medieval warfare afaik, but yeah a flail could break bones or knock someone unconscious or outright kill them with enough force to the head.
It’s a club on steroids. A primitive and brutish weapon but undeniably effective. It’s like the scientific answer to the cave man “me hit hard” question.