Most notably, if a triggered ability asks its controller to pay a cost, you pay that cost for the copy if you wish to have it paid
MTG's Wurms tend to be gigantic worm-beasts that tend to bring to mind creatures from Dune or Tremors (just like the iconic Craw Wurm from Alpha), but this guy is very clearly a dragon sleeping in the desert
If you cast a creature spell this way, it gains haste until you lose control of that creature (or, in rare cases, you lose control of the creature spell while its on the stack)
These effects are a lot more useful for when youre just trying to empty your hand and draw seven new cards repeatedly.Due to graveyard hate, you most likely need a back-up plan other than just Echo of Eons
Careful Study, though putting you back a card, nevertheless allows for much needed filtering