Captain Ian, The Tyrant

Whenever one or more Pirates you control deal combat damage to a player, choose one —
• Create a Treasure token.

• Exile the top card of that player’s library. Until end of turn, you may cast it, and you may spend mana as though it were mana of any color to cast it.

At the beginning of your upkeep, if you control five or more Pirates, you may cast a Pirate card from exile without paying its mana cost.