Why is this script not changing the players team?

while wait() do
    local Players = game.Players:GetPlayers()
    local MonsterKing = Players[math.random(1, #Players)]
    if MonsterKing.name == not game.ServerStorage.LastMonsterKing.Value then
        game.Players[MonsterKing.name].Team = game.Teams["Monster King"]
        game.ServerStorage.LastMonsterKing.Value = MonsterKing.name
        break
    end
end

I'm trying to make it so that my game will randomly choose a player to be the monster king while making it so they were not the monster king last time.