You can Tribute Summon this card face-up by Tributing 1 "Magical Musket" monster. During either player's turn, you can activate "Magical Musket" Spell/Trap Cards from your hand. Once per turn, during your opponent's End Phase: You can draw cards equal to the number of "Magical Musket" Spell/Trap Cards you activated this turn while this card was face-up on your field. You can only use this effect of "Magical Musket Mastermind Zakiel" once per turn.
