There’ll be two teams with 5 members called heroes/champions. League of Legends is a Multiplayer Online Battle Arena or MOBA with RPG Elements that sets each player in a third person character.
But for other MOD skins out there, we cannot guarantee their reliability especially if it offers other stuff aside from cosmetic modification. MOD skins LoL Pro offered here just aims to improve the visuals of the character and nothing more. As long as this issue doesn’t affect Riot Game’s business, they would still allow cosmetic modification but this can change anytime.
It will only be a concern if the MOD skin affects the performance of the character adding strength and power to the character itself. Riot Games, the creator of League of Legends, does not ban players from playing with new MOD skins as long as it is used for aesthetic purposes. Moreover, you may also want to have a Champion-themed cover photo to add a ‘positive effect in your gaming presence.