Tyris, Summoned by Emrakul

Tyris, Summoned by Emrakul cost {x} less where
x is the number of card types in your graveyard
When Tyris, Summoned by Emrakul enters the battlefield create three 2/1 colourless creature
eldrazi tokens
Devoid, Trample, Protection from instants
"They think I'm gone, but my impact will always
remain" - Emrakul