When Ertai Resurrected enters, choose up to one Counter target spell, activated ability, or triggered ability
Mask of the Schemer can make your attacker bigger and give you plenty of card draw
The mini-Fact or Fiction (or upgraded Divination, depending on who you ask) has started showing up in control decks in both Modern and Legacy, leading to the price increase
Nobody would ever be willing to drop a thousand dollars on a card that WotC could turn around and put in a set tomorrow
By round two, you can have her sing a cost three song thanks to her Singer ability
Otharri, Suns' Glory Yes Otharri, Suns' Glory is mana-intensive, but effects that generate multiple tokens tend to be that way, and when they add immediate attackers, they are excellent