You have at least ten Gates with different names in library or on the battlefield under your control.
Mana Needed
({12} magic symbol) ({G} magic symbol) minus ({1} magic symbol) for each unique Gate you control available.
Steps
Cast
New Frontiers by paying ({9} magic symbol) ({G} magic symbol) minus ({1} magic symbol) for each unqiue Gate you control.
Resolve
New Frontiers, causing you to search your library for that many Gate cards and put them onto the battlefield tapped, and allowing each opponent to do the same for basic lands.
Activate
Maze's End's second ability by paying ({3} magic symbol) , tapping it and returning it from the battlefield to your hand, searching your library for a Gate, putting it onto the battlefield and causing you to win the game.