Prinz Eugen

When Prinz Eugen enters the battlefield,
exile another target creature or artifact until
Prinz Eugen leaves the battlefield.
You may cast that card for as long as it
remains exiled, and you may spend mana as
though it were mana of any type to cast that spell.
Admiraal! Is it the Rhine Exercise? ...Ah..
So I was mistaken.. It's okay! I'll still work hard!
Leave it to me!