Gain control of target nonartifact, nonblack creature
If it enters at the same time as a Swamp or Mountain when you control no other Swamps or Mountains, it will enter tapped
Shortly after this card was previewed, it dawned on most Modern players that this One Ring to Rule them All would become One Ring to Rule Modern for several reasons: 1) almost any deck can play it and/or wants to play it, 2) its ETB ability single-handedly shifts the state of the game, 3) it provides massive card advantage, 4) it's abusable
What affects the value of Stormscale Scion
The cards could be notably mid, and because of the art and IP, the demand should be good
Second, some of the cheap mythics (like Prossh, Skyraider of Kher) are actually pretty valuable in foil, since Masters 25 is their first foil printing and the primary demand for these cards is from Commander, and Commander players love their foils