If anyone cares to do some SCIENCE!, I'd love to a) find out the order of deathrattles and b) get confirmation that Rivendare does not double Deathrattles that triggered from an effect which killed him as well.
a) Things trigger in the order they were first played, so a Harvest Golem followed by a Dark Cultist on an empty board, dying simultaneously, would spawn a Damaged Golem and then give it a health buff. Now consider a Baron Rivendare played after the Cultist. Do the additional Deathrattles stick to the order of their original minions, or do they go off on Baron Rivendare's "turn"? My suspicion would be the Deathrattles themselves are modified (in other words Rivendare's effect is a passive aura, not triggered), so both go off on the Deathrattle minion's turn. In the above case this would result in two Damaged Golems and THEN two health buffs, so either could receive one or both buffs. If instead Baron triggered the additional Deathrattles himself, there could be counterintuitive results if Baron was put on the board before or in between the Deathrattle minions. But I'd like confirmation.
b) Assuming Baron's thing is a passive effect, he will have been removed from the board by the time the Deathrattles go off, so they should not be affected by him. Again, I'd like confirmation.