Altast, Emperor Supreme

Altast, Emperor Supreme costs {1} less to cast for
each empire permanent you control.
Eminence — If Altast, Emperor Supreme is in
your command zone or on the battlefield,
whenever you cast an empire spell, you may
search your library for an empire card, reveal
it, and put it into your hand. If you do, shuffle
your library. (Empire cards are Crown of Empires,
Scepter of Empires, and Throne of Empires.)