Mercurial Spelldancer can't be blocked. Whenever you cast a noncreature spell, put an oil counter on Mercurial Spelldancer. Whenever Mercurial Spelldancer deals combat damage to a player, you may remove two oil counters from it. If you do, when you cast your next instant or sorcery spell this turn, copy that spell. You may choose new targets for the copy.

Flash When Tishana's Tidebinder enters the battlefield, counter up to one target activated or triggered ability. If an ability of an artifact, creature, or planeswalker is countered this way, that permanent loses all abilities for as long as Tishana's Tidebinder remains on the battlefield. (Mana abilities can't be targeted.)

Surveil 1. (Look at the top card of your library. You may put it into your graveyard.) Draw a card.

Return target creature to its owner's hand. If its mana value was 3 or less, scry 1. (Look at the top card of your library. You may put that card on the bottom of your library.)

({T}: Add {U}.)