In Shadowmoor , every single legendary creature qualified
That said, it would be unwise to count any of these lands out before testing
When Vampire Spawn enters, each opponent loses 2 life and you gain 2 life
But when those myths are repeated so often that they seem to be elevated into canon, and if that pseudo-canon makes the actual authors hesitant to write about this part of continuity, we've got a problem
During your turn, as long as you've sacrificed a nontoken permanent this turn, you may play cards exiled with this creature
In fact, this main set Sauron is so good that if you're looking for a power boost then I would put it in the command zone and put Sauron, Lord of the Rings in the 99, they provide similar value to the deck but Sauron, the Dark Lord is simply stronger