Astorius, the Astrologer

Flying, vigilance
When Astorius, the Astrologer enters the battlefield or attacks, you may exile target
nonland permanent.
Astorius, the Astrologer costs {2} less to cast
as long as an opponent owns an artifact in exile,
has haste as long as an opponent owns a creature
in exile, has hexproof as long as an opponent
owns an enchantment in exile, and has
{2}{u},{t}: Draw a card as long as an opponent
owns a planeswalker in exile.