Jayna, the Night's Fang

First strike
When Jayna, the Night's Fang enters the battlefield, she deals 3 damage to each creature
you don't control.
Whenever Jayna attacks, you may draw a card. If
you do, discard a card, then add an amount of {b} to your mana pool equal to the converted
mana cost of the discarded card. Until end of
turn, you don't lose this mana as steps and phases
end.