Many staples have already had reprints, such as Farewell, but I think the Legendary Lands from Neon Dynasty are strong contenders to start ticking upwards for a while, now that they are no longer Standard legal
While the deck is definitely focused around creatures, there are also a number of notable noncreature spells
Day of Black Sun is one of the early highlights of Avatar for Commander, so this is a fine pick for a promo card
However, if you cast See the Truth from anywhere other than your hand - lets say the graveyard thanks to something like Snapcaster Mage - then you get to draw three cards
In fact we have enough cards that make and interact with Treasures now that you can build a whole EDH deck around them, and I can bet you that Xorn is going in every single one its currently the top red card from the set at 1600 EDH decks on EDHREC, and the third most popular card overall