Ashad, The Lone Cyberman can grow into a threat simply by using its effect, and while you wouldn't usually sacrifice creatures that are actual permanents, you can utilize your creatures if you're in a pinch and this means you'd be doubling up on a powerful artifact
Trance ability allows her to mill two cards at the beginning of the combat phase in order to gain flying, which means she can't be attacked except by other creatures with flying
Its a self-mill for Green, dumping three instead of six cards into the graveyard
Thats about as good as a Concentrate, so Memories Returning is a nice value spell
This makes the commander cards extremely powerful since youll be able to gain their benefits without paying their mana costs
The same is true of the Cat drop, where Regal Caracal's Amonkhet printing is $0.47, while the Secret Lair version is $14