You need to operate at sorcery speed for this to be effective
Sensational Spider-Man Sensational Spider-Man is already cool as a 3/3 that taps creatures with a stun counter
There's plenty of ways to get lots of artifacts out and pump this guy, but this is like the same as another card in this set, basically 2/2 for 3 with an ability that gives it counters and basic evasion, which is pretty same-y
Samut takes full advantage of this, granting other creatures the player controls +X/+0, where X is their current speed, as well as making non-creature spells cost X less to cast, where X is their current speed
They are avoiding giving us the exact rarity, as they did with The One Ring, because that data point unlocks a whole lot of additional information for us: number of packs, how many copies of a card exist, things like that
Magic Amonkhet card list & price guide