In the past different worlds were said to have more powerful or wild mana, does the opening of the Omenpaths erase this lore? Some planes had weak types of mana do the Omenpaths let stronger mana flow into them? Its just that previously lore onvolved various mana qualities andvwpuld just like to lnow ot that part of the metamagical physics has been changed?

To the best of my knowledge, mana doesn’t flow through omenpaths.

Regarding making a list of silver border cards that are now eternal legal: as much as I want this, I think it's a very bad idea to make such a list and not provide black border printings of such cards. Maybe when the time comes they could go on The List that goes in boosters or something. But it seems to me that the current rule of "a silver border means it is only for casual play" is a good line to hold if there won't be a black border update for cards that's no longer true for.

If such a list exists, we can look for opportunities to provide black border versions, but trying to get them all would be very difficult. It also doesn’t erase the issue of playing with a silver bordered version.

I was unsure about the ending of March of Machines but was fine about it after all. but Aftermath has made it feel really bad now. why just erase these characters from relevance? especially ones you've done nothing with since their inception.

Losing their spark doesn’t mean they won’t be relevant.

Speaking of Erase (Not the Urza's Legacy One) from your Drive to Urza's Work, a high five to whoever went back in Oracle and updated the flavor text to cross out the names that have since become cards. Keeping the Un-jokes up to date is one of my favorite Oracle easter eggs.

I believe that was the work of Matt Tabak.

You asked for input on whether I would erase companions from existence if I could. Definitely not! I think they're a mistake because they're very powerful, and very consistent: Mana permitting, you always get to play your companion exactly when you want to. But it's the kind of mistake Magic needs to make now and then to get a sense of where the boundaries need to be. I 100% support your philosophy of trying new stuff and occasionally failing. I think it's essential to the health of the game.

Thanks for the input.

Silver-bordered question: How does Stet, Draconic Proofreader interact with permanents that have multiple names? Do you choose which name to erase a letter from, or does it apply to all of its names? Also, if my friend were to legally change their name in the middle of a Magic game after I've activated Stet, would the ability carry over and still have erased the first letter of their new name?

It erases the first letter from the name of your choice. And how slow is your game that your opponent is able to change their name in the middle of it? : )

Can you show me all the cards from the "Friends" block if you're able to erase my memories immediately afterward (but still keep the emotional impact)? I dunno, it might be too much excitement.

We haven’t cracked that technology just yet. : )