This set, and the cards within it, has had a very lasting impression on the game as a whole and Magic: The Gathering hasnt been the same since.
I feel like the ability got gain life and eventually summon all your elves puts great pressure on your opponent to do whatever necessary to prevent that from happening
Its extreme value stems from a perfect storm of competitive necessity and emotional nostalgia
Fevered Visions suffers when your opponents can dump their hands, just as with old school Black Vise decks, which is why they often used Stasis
the fact that he helps you out when he dies as well by returning something to your hand makes taking him out with removal a less positive trade for your opponent
On top of that, its got cycling to keep your hand fresh if you draw it early or already have one in playand yes, you can run as many copies as you want, just like a Shadowborn Apostle with a twist