Davros, Creator of the Daleks

Dalek spells you cast cost {x} less to cast
where {x} is the number of nontoken Daleks
you control -2 for each nondalek creature you
control.
Whenever a nontoken Dalek comes onto the battlefield under your control, create a 1/3 black
Dalek creature token with deathtouch.
{1}{b}: Tap target creature. You may use this at
any time you could cast an instant.