Being the only game in town for no-art lands would make Unstable more similar to Unhinged or Unglued , where if you wanted a certain subgroup of basics for your deck, you pretty much had to buy the set (or at least the lands from the set, which would force someone else to crack a box of the set to sell them to you)
(In Final Fantasy VII Rebirth, there are even more!) Needless to say, the Secret Rendezvous variant we're focusing on for this list is Aerith's
Besides that, it makes stuff to feed to Skullclamp
Old Beanie, as I like to call it, is a superb addition to any deck that plays permanents off the top of your library, such as Atla Palani, Nest Tender and Vaevictis Asmadi, the Dire
Giving all your dragons haste is already incredible, but stealing everyone elses dragons when it enters can lead to absolutely absurd swings