I mean, it would be awesome if Vihaan could turn a huge haul of Treasures into 3/3s and then have Olivia turn them all (minus the two you sacrifice) into 5/5s right away, but it sadly cant be done until you go back to your main phase, which is really a bummer
I just think the card is well executed it being an artifact plays well with Urzas Saga, Improvise and Springleaf Drum, and unlike Thalia, Guardian of Thraben where youre locked out by the tax, you have the choice with Esper Sentinel which presents interesting in-game decisions as you have to balance the tax on the mana versus providing your opponent with card advantage a similar decision to that of being on the play or on the draw
3 Mangara, the Diplomat Mangara, the Diplomat is a great draw engine thatll have your opponents thinking twice about attacking you and casting spells
If you can double spell in a turn, then you get two cards, a +1/+1 counter and temporary flying
But that ability to go under the radar - true to the deck's name - will only help your win rate