From our Deckbuilding Guide to our Advanced Strategies Guide, you should be all set to play the game competitively from here on
I play mono-blue faeries, so this list is going to be biased, but with that being said, I have a pretty good idea how all these cards work best
Ondu Spiritdancer Who doesnt love a copy
I dont think Ill get to use the reverse side of The Everflowing Well too much with all my legendary permanents, but Im happy enough with the card draw, self-mill, and mana-ramp aspects of the card in addition to being a legendary artifact
Animate Dead, for example, is weaker to removal, but a lot easier to use in a combo
All of these cards are capable of becoming the cornerstone of the right deck, and all have spent time at $20 or more