Proteus, the Ur-Kaiju

Eminence — Whenever you cast another Kaiju
spell, if Proteus, the Ur-Kaiju is in the command
zone or on the battlefield, search your library for
a Kaiju spell with the same converted mana cost, reveal it, and put it into your hand. Then shuffle
your library.
When Proteus, the Ur-Kaiju enters the
battlefield, return control of all permanents to
their original owners.