Chesstale Sans x Female Reader

You have already been through a pacifist run for normal Undertale after curiosity about Mtt Ebott, but something doesn't feel right and when you get to the surface everything goes wrong so you do the only thing you can think of and have Frisk reset. You end up at the beginning of the game only to realize Frisk isn't there and the monsters aren't the same. They are chess players. You are curious about what Sans would be like here, and unexpectedly fall for him even though in undertale he was more like an older brother kind of guy. White moves first, so you have to make the first move the entire time and hope to win the game.