Classic Battle Royale

Vayne (LoL) Overall the non-mage Demacians are pretty evenly matched and an argument could be made for any of them to be the winner (aside from Quinn, rip), Fiora and Xin are the most skilled fighters while Jarvan and Garen have the best physical strenght alongside the best armor.

Imo tho the winner would be Vayne as she is still fairly comparable to Xin and Fiora when it comes to prowess, but is also able to constantly engage into fights with werewolves or other magical beings , which should put her somewhere close to J4/Garen in terms of raw stats, coupled with her likely having the most experience and the best weaponry out of them i think she would be the winner.