most of them are permanents, but there are also some sorceries
You can't pay that amount multiple times to multiply the effect
Ive played against it a couple of times in Brawl on MTG Arena, and if you cant deal with Narset before it attacks, it's pretty much game over due to its ability that lets it target non-creature spells from any graveyard, exile them, and cast a copy for free
That's totally fine, though, since this is basically three very common abilities on the same card, and depending on where in the game you are, you can just choose the one that suits you best
Let's say you get Astral Drift on the battlefield alongside Unpredictable Cyclone and Eternal Witness
Whether it's Clue or Cluedo to you, you'll have the opportunity to solve a murder with Magic at its heart