Ki, Kobold Hunter

As an additional cost to cast Ki, Kobold Hunter,
you may sacrifice any number of creatures.
Reach
When Ki, Kobold Hunter enters the battlefield,
if the additional cost was paid, you search your
library for a creature or artifact with a converted
mana cost of X or less, where X is the number of creatures sacrificed this way and put that card in
your hand. Then shuffle your library.