I usually like to run one personally (just one though) - but honestly in my experience it tends towards 80% or so of the time when cast it's just overkill. I do like having the one to turn 0/2 totems into threats though. (similar to why other one turn +X/+0 buffs are wonderful for shaman)
Piloted Shredder is a top tier 4 drop so if you got 2 of them, add them in lieu of the Unbounds.
You can also just use Alex in his place. Better in some matchups, worse in others.
I've managed to pull 3 Malygos's, 1 golden, (1 golden and 1 normal in the same big batch, 1st Malygos was my first ever legendary). Lots of doubles so far, TBK, Thalnos and the Maly shenanigans. Kind of annoying as I still need some of the good classic ones (Rag, Ysera, Tirion, Jaraxus, Anotonidas).
Time Rewinder is so much fun to play with when you get it. Earlier today I was able to lock down a combo druid with Loatheb for 3 turns to secure a victory which would have made me smash something if it were me losing. RNG is gonna RNG, but fuck it. RNG is what Hearthstone is all about, just embrace it!
That depends on if you Arena or not. Arena only rewards GvG packs. I use gold for Arenas and any excess goes to classic packs.
