Leader Monster

A Leader monster is a sub-type of monsters, introduced by LHK.

How They Work
Before the duel starts, a player can place a Level 4 or lower Leader monster from their Deck to the Leader Zone. Once during each of your turns, you can place 1 monster from your hand with 1 or 2 Levels higher than the monster on the top of the Leader Zone. Monsters in the Leader Zone are still treated as monsters, meaning that they can attack or activate their effects. If an Extra Deck Monster, except an Xyz Monster, is Summoned using the monster on the top of the Leader Zone, the Material that is in the Leader Zone cannot leave the Leader Zone (sent to the GY, banished, shuffled into the Deck), but instead the monster Summoned must be on the top of the Leader Zone, but then it goes back to the Extra Deck in the end of this turn.

Examples
TBD