Teyn, King of Coin

When Teyn, King of Coin enters the battlefield,
you become the monarch.
At the beginning of your end step, if you are the monarch, create a colorless Treasure artifact
token with "Tap, Sacrifice this artifact: Add one
mana of any color to your mana pool."
At the beginning or your upkeep you may
sacrifice a colorless Treasure artifact token to
create a 1/1 black Assassin creature token with deathtouch and haste.