(These tests we're ran on very small sample sizes. The goal is to look into when there is two Sylvanas' on the board at the same time. Each test was only ran Five times each. We know this isn't great for you statistic majors, but when you can find something that disproves your theory, that works nicely and at least its something to give you an idea of what to do)
Side One always has placed Sylvanas on the board first. This Sylvanas will also attack first into the other Sylvanas on Side Two. This test considers that there is one minion on each side of the board other then Sylvanas. Once the first played Sylvanas attacks into the second played Sylvanas, the Second played Sylvanas will death rattle first, followed by the first placed Sylvanas. In these situations its usually advantageous for the First placed Sylvanas, who is attacking into the other Sylvanas as he will Death Rattle second. (This happened 5/5 times)
Side One always has placed Sylvanas on the board first. This Sylvanas will also attack first into the other Sylvanas on Side Two. This test considers that there is ONLY one minion on ONE side of the board. (The same side as the first placed Sylvanas) In this situation, the first place Sylvanas attacks into the second placed Sylvanas, he will once AGAIN come out in the better situation. His death rattle will happen after the Second placed Sylvanas.
You might think, perhaps minion amounts don't matter? Why are u testing with different minion amounts? Because it does matter as I will show soon! (These results happened 5/5 times)
Side One again always places Sylvanas on the board first. This test is with Two minions on Side Two, and One minion on Side One. The first placed Sylvanas has only one minion, while the other side has two, other then Sylvanas. The first placed Sylvanas then proceeds to attack and kill one of those two minions, leaving her with 5/x health (where x is less then 5, i.e. a 5/3 Sylvanas) Now the second placed Sylvanas attacks into the first placed Sylvanas on Side One. What do you think happens?! Will the first placed Sylvanas get the better situation, with his death rattle happening second? Or is it something different?!
It turns out, this situation can have both results. Some times Side One has the first Death Rattle, and other times Side Two does. We didn't expect this at all. Why is this the case? At this point, perhaps there is a reason. Maybe something to do with minion tiers, who went first, exact health amount, cards in hand or something that I didn't test for yet. Basically I don't know why this situation is random! However we have seen both results while trying to keep everything else the same.
Side One once again places Sylvanas on the board first. This test is with Three minions on Side Two, and One minion on Side One. The only difference here, is that Side Two has THREE instead of TWO minions. Now the Sylvanas played first attacks into and kills one of those three minions. Now there is two minions other then Sylvanas on Side Two. The Sylvanas on Side Two (Who was played second), attacks into the First Sylvanas who has 5/x (Where x is less then 5, i.e. 5/3) from hitting and killing a weaker minion the turn before. Now what happens? Is the result random, because we've only changed the amount of minions on one side? Didn't I say earlier minion amounts matter.. so maybe its not random this time?
If you did figure that out, congratulations. Because as far as we tested, this time it is not random. When there are three minions instead of two, the First placed Sylvanas will get the advantageous position again. He will steal second. So in this situation, where you placed your Sylvanas first, and there were three minions on the opponents board, feel free to attack and kill one, if the other Sylvanas attacks you, your death rattle will happen second, taking back a minion stolen.
Why does three minions make a different result then two minions? I don't know. (This result happened 5/5 times)
End Hypothesis : In three tests we received the same result every time. Something happening 5 times in a row is fairly rare without a reason. I hope to test these situations more and give better percentages on this being true and knowing something is the reason for sure. This is just giving you a general idea on some situations involving Sylvanas. Is this for sure correct? No, I don't know for sure, I'm just sharing with you the statistics of what happened, and my guesses on what they mean. These tests we're done with both myself and megablue. Thanks for taking the time to read this!
Fun Fact : If you have a Baron Geddon and a Healing Totem out, the 2 damage and the 1 heal will happen at the same time! This keeps alive your 2 health minions! ^^