I dunno when this post was made but id like to add to it
The Balrog, Durin's Bane's first ability counts every permanent that was sacrificed this turn, by any player
Tidus, Yunas Guardian has the ability to move a counter from any target creature onto another target creature, and hes also got the unique Cheer ability, which allows him to draw cards and proliferate whenever one or more creatures (that the player controls) deals combat damage
If you do not cast it, that card will remain in exile
If an effect allows you to cast (rather than play) a specific modal double-faced card, you cant play it as a land
SOI takes place during the Gatewatch arc and sees some of the gang on Innistrad investigating what is making the things that go bump in the night a little weirder