Emperor Mihail II is a boon to Merfolk tribal decks, and it can just as easily climb to the top of the pile for mono-blue Merfolk Commanders
Also, thanks to its increased toughness, Vivi should be able to hold its own in plenty of combat encounters
It is safe to say that many players find hexproof annoying, which is why Wizards has moved away from it a little and moved towards using ward instead
The trickiest part about drafting Grixis is balancing all three, and theres no easy way to determine which is the most important at any given time
Obviously, wed love to see promos as good at this, but only if Wizards can appropriately manage supply
If that enchantment is an Aura, you may attach it to the token