msem-instigator

Whenever you cast a spell you don't own, you may pay {1}{U}. If you do, put target nonland permanent on top of its owner's library.
{2}{B}: Exile the top card of target opponent's library face down. You may look at and 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.