What is the best fighting knife solely as a weapon?

I'm doing research for a story I'm writing that involves a decent amount of knife fights and I want to know what knife operates best as a weapon. I find that there aren't many good answers to this question because people in the knife community don't wanna come off as some LARPy losers who are obsessed with self-defense and whatnot plus the fact that most knives have multiple functions outside of just being a weapon. But I want to eschew the practical utilities of a knife and look at it solely as a combat weapon. (also I have no intention of trying to buy said knife so don't worry about price or if it's legal to get)