An un-rules ruling(s) that came up in a game I really played recently. I have Another Aether Vortex. My opponent's library's top card is an Augment creature. There's a host on their battlefield. A. Can the augment attack since it kind of has stats? B. What if anything happens with the augment's abilities? C. Can it augment the host?

Augment cards function similar to auras. If they are somehow on the battlefield, but not attached to another permanent, they are destroyed by state based effects and go to the graveyard. If you have Yet Another Aether Vortex, you’ll get your turn over the top card of your library and if it’s a permanent, it will also be on the battlefield. And no, it will be too late to augment it to a host.

Hey Mark, Acorn question: If I become a card due to my Form of the Approach of the Second Sun, do I have any rules? Can I cast myself with Future Sight (even if I stop being a card once I enter the stack, because I left my library)? Is there anything that I can do with myself being on the battlefield due to Yet Another Æther Vortex?

You don’t have rules text or a mana cost, but I have ruled you are a planeswalker. If you get onto the battlefield with Yet Another Aether Vortex, you’ll need something like Rules Lawyer to keep from being destroyed by having 0 loyalty.

What happens if I'm in my library and yet another aether vortex puts me in play? Do I die from not having loyalty?

Yes.

With form of the approach of the second sun and yet another aether vortex, what is the player's card type? Are we still supposed to be planeswalkers?

You are a planeswalker card when you become a card.

So, with Form of Second Sun, we're a planeswalker card. If I'm on top of my library, with Yet Another Aether Vortex around... wouldn't that make me a planeswalker with zero loyalty on the field and then I have to leave the field as a state-based action? Or do I not need loyalty to myself?

No, you will leave the battlefield, and thus the library, and thus stop being a card.

If you somehow become a planeswalker card on the battlefield through yet another aether vortex + form of approach of the second sun, and a player casts a hero's downfall on you, do you lose the game since they're also "destroying a player"?

No. You stop being a card, but you don’t lose the game.

has the Rules Manager ever -- just as a thought experiment -- investigated if and how Yet Another Aether Vortex could work in black-border (assuming, of course, changes to the Comprehensive Rules), including weird edge cases and edge conflicts? or do they only put in that work if the change actually has to be done?

As the Un-Rules Manager that’s had to answer lots of YAAV questions over the years, it’s nowhere close to working in the normal rules. I’ve had former Rules Managers refuse to play with the card because it makes their head hurt.

Traditionally, cards that wouldn't work in paper's black border mechanics appeared with a silver border. Was any thought given to making the Arena-only cards silver bordered, to be used only in Jumpstart Historic Horizons or Direct Challenge? A lot of digital-only players were enjoying watching Historic grow into a format more like Pioneer or Modern, and unique cards irrevocably breaks us off that path. Just seems like a fine opportunity to introduce silver border to Arena was sadly squandered.

What constitutes silver border is a complex topic, but I think you’re talking about the cards that don’t work within the rules (like Yet Another Aether Vortex). The Arena-only mechanics can work in the black border rules. Arena couldn’t do them if they didn’t. The issue with them is practical logistics, not functionality.

What silver bordered card should I build a deck around?

Yet Another Aether Vortex.

What happens when psychic network and yet another aether vortex are in play at the same time?

It gets weird. You can have permanents on the battlefield, but not be aware what they are. It’s kind of like how Illusionary Mask and Camouflage originally worked except it’s flipped in that everyone *but* you knows what it is.