Henry, Twisted Mind

Partner
When Henry enters the field and whenever a
creature is removed from play by a Black Sorcery
you casted, create a 0/1 Black Flying Bird-Token.
When paying for the cost of a Black Sorcery, you
may sacrifice a Black Flying Bird-Token to lower
it's casting cost by {b}. Only do so once per
paying a Sorcery's casting cost.