Enter, Noyan Dar, Roil Shaper, a 4/4 Legendary Merfolk Ally with a casting cost of 3WU. His ability reads:
Whenever you cast an instant or sorcery spell, you may put three +1/+1 counters on target land you control. If you do, that land becomes a 0/0 Elemental creature with haste that's still a land.
Wow, that seems good. As underwhelming as Allies have been with the recent spoilers, this card is actually rather cool. A 4/4 for 5 mana isn’t incredible, but he has Ally support around him. The question is: can this guy be Standard-playable? It doesn’t take much to get value out of him, of course. Any instant or sorcery can turn one of your lands into at least a 3/3. The opportunity cost here is pretty low.
In Limited, Noyan Dar is going to be pretty good, as who doesn’t want to bash some people in the face with lands? You only have to get around to animating one or two lands to make playing him worth it, and if one of those is a man-land, then you’ve definitely gotten your value.
In Commander, I really like the Merfolk Legendary. Sygg, River Guide makes for a pretty solid Merfolk Tribal deck, but a blue-white control deck with Ally support seems legitimate. A lot of the great Allies are in White to begin with. Jwari Shapeshifter is probably the best in blue. This seems like a legitimate Commander to me. It does, of course, leave you pretty open to boardwipes - something that you’ll always have to contend with. But when we know all this set has to offer, this seems like a fun brew to play around with.
The other thing here is that there are plenty of man-lands in Commander to choose from. You can even choose to put 3 +1/+1 counters on a land that already has counters on it. Forbidding Watchtower and Faerie Conclave get a lot scarier when they get counters piled on top of them, and Celestial Colonnade goes to town. Some Esper Control brews in Commander may consider Noyan Dar to make their Creeping Tar Pits (which are unblockable) even scarier.
The saddest part is that Noyan Dar, like Zada, Hedron Grinder, is a creature that you really don’t need to play in an Ally deck and in fact doesn’t even really work well in an Ally deck. Still, Noyan Dar looks like a solid mid-range card for some control decks. The Tazeem lullmage is probably going to end up being a bulk rare, but a decent Commander.