This flexible land can be tapped for a colorless mana, or one mana of any color at the cost of one life, as long as that mana is being spent to pay for the mana cost of a Vampire spell
It also has a flashback option
ST07 - Big Mom Pirates Recently, in Asia, ST07-001-charlotte-linlin has gotten a minor resurgence in play
However, since they can be made at instant speed, depending on the stolen cards, she can largely get a lot of value out before she is taken out and is a great theft commander as a result
The way challenging works is a ready (untapped) character exerts and chooses an opposing exerted character to challenge, and then both cards compare their strength (attack) and willpower (defense) values to each other (meaning the attacker automatically gets hit back by the defender)
I also bring it in against decks that play Ethersworn Canonist as an additional way to kill it