You can supplement powerful instants and sorceries to up the potential of this card, but more often than not, even the opponents cards will be enough to make Mysterious Stranger worth it
This Magic: The GatheringFINAL FANTASY Scene Box, Children of Fate, contains 6 traditional foil borderless scene cards, 6 art-only scene cards, 3 Play Boosters, and a paper display easel
Ezzaroot Channeler Ezzaroot Channeler provides lifegain decks stellar ramp and even a bit of self-enabling
Either way, you get an advantage from it but I think this is the better Retreat for this deck
Those of us who tried it have found varying success: Jason Waddell has written articles on it and I've personally found the archetype to be fun
All you need is a card like Heartstone or Zirda, the Dawnwaker to reduce the cost of Sliver Queens effect, then cards like Earthcraft or Gemhide Sliver + a haste enabler, and you have access to infinite 1/1s