They "remember" any counters they had on them, any choices made when they first came into play, and whether they were tapped or untapped when they left play
The card is a black damage-dealing instant that can hit a creature or player for four damage and gain its owner four life
Zirda, the Dawnwaker is another powerful effect in cycling decks but it also cuts off the ability to have cards like Fluctuator and other potential enablers or payoffs
An alternate art Magic card is legal for tournament play if it has a black border and isnt damaged so much that it marks the sleeve it's in
There are enough creatures with those types in Black in this set that it will be pumping 3-5 of the creatures in your deck, and sometimes more, but the real value comes from the ability to make 1/1 Skeletons, which, if the Deathpriest is in play, will of course be 2/2 skeletons