Tahroviin, the Eldest

Flying, first strike, ward {5}
Eminence— As long as Tahroviin, the Eldest is in
the command zone on on the battlefield,
whenever you cast a dragon spell you may search
your library for a dragon creature card with
converted mana cost equal to or less than the cast
spell and put it into your hand.
Whenever a dragon enters the battlefield under
your control scry 1