Looks like the set is starting to leak. The green card is Court of Abundance and reads as follows:

2GG
Enchantment
When Court of abundance enters the battlefield you become the monarch.

At the start of your upkeep you may put a land card from your hand onto the battlefield. If you are the monarch you may put a creature or land card from your hand onto the battlefield instead.

Seems like it is right up there with something like Oath or a one sided show and tell. If you can lotus this out turn one or some other nonsense, Monarch will draw you an extra card for your trouble as it is very hard to remove from a player in vintage (at least right now) as most people do use haste creatures to steal it. If you survive a turn you can put GB or whatever into play and go off. Even if you don't combo out it has a lot of long term value if you maintain it.

I saw this card and really like it. I can see some downside vs things like vengevine, and you may want to run some hasters yourself to hedge against the steal, but it's a strong effect for not much mana. It's a bit tough to compete with "I get my creature now" effects like Natural Order or Show and Tell...and if you are waiting for upkeep, Oath is probably just superior, but it's a nice card.

I don't think this seems goods at all.

You must remain the monarch.
Costs 4 mana.
Must have the fatty in your hand (and if it's not a fatty, it's not worth very slowly paying 4 mana for).
This card's upside is you can use it twice or 3 times.

• Monarch can be stolen. How easily a person thinks that is is debatable, i would say relative ease.
• 4 mana is ridiculous, you can be playing a lot of 4cmc cards that do other things. You can Natural Order for Progenitus if we're talking about fatties, which can either be with mana dorks or in an elf shell - and that doesn't sound too great but i'm also thinking you need blockers to protect your monarchy so.
• You must be playing enough fatties to have it in your hand. The purpose of Oath is to play any shell you want and only need 6 actual cards for it. You're going to play how many Courts to cheat out Griselbrand? And then how many Grisels and other mega monsters? They're all dead cards without Court, and if it's not a dead card without Court then you don't need Court.
• Using this multiple times sounds fun but it doesn't sound like a strategy. Using it twice means one monsters was not good enough (this is also true of Oath, sure) and you continue to fight for monarchy. And, see above paragraph, but you really have to have a bunch of otherwise-dead cards in your deck in order to use this repeatedly.

You could drop low-cmc creatures with it to slowly accrue advantage but i don't think that's a Vintage format strategy with Workshop, Hollow One, Tarmogoyf, whatever.

The fact it only does your hand completely kills the card as far as I can see. Because instead of 2 oath monsters you now run 12? So the effect is worse than oath but its also twice as expensive and keeping monarch is hardest against shops and bazaar aggro, the decks oath is supposed to be good against. There is no way it goes in anything that already exists and I very much doubt it is going to be good enough to build around. One easy way to think about this card is show and tell with more steps. No one plays show and tell so why would we play a worse version in worse colors?

For the same reusable upside, I'd almost rather sneak attack. I like the card, mainly for the cheap monarch ability and the "cheat" mana ability - but doubt it's Vintage relevant with other options we have.

Unlike Show and Tell, this card can sit in play a few turns while you wait to draw or tutor your payoff creature. That’s something, at least.

I agree it’s unclear how to build around this card where Oath isn’t simply better. You’d want/need to run a lot of creatures yourself, some castable (otherwise why not just use Oath?) and some expensive that you’re hoping to cheat into play. BUG with DRS and other disruptive creatures along with some finishers like Griselbrand? I don’t know.

I’m not going to lie, this seems like a fun EDH card that’s more than a little suspect in Vintage proper.

@evouga

If it cost half as much mana it would probably be good in hoagaak as is seems iffy.

If you can stay monarch it’s good.

All of the Court cards seem really, really strong in a hard control shell. They each provide card advantage and a win condition that usually requires nothing more than sitting back and protecting it.

Imagine you drop Moat and you have the Black or Blue Courts out. You can just sit back behind a wall of countermagic and win. The Blue one, in particular, is 3 mana for a 4, maybe 5 turn clock. Is this enough to bring some kind of old-school UW Control back? Can Weismann live again?