First victory against Rainbow today, using this deck - though I did add an extra Quintessence (protect both oty and druid) and a second Eternity (lost a couple fights when Eternity was my last card!). I did not get mastery, his insane amount of hourglasses kept throwing creatures at my bone wall and I ended up relying on empathy to survive. Decked him out, otherwise I probably would have lost. I'm a new player, maybe 3 weeks, and appreciate all the help.
I've got the deck about half upgraded:
Firestorm
Bone Wall+
one Feral Bond
all Hourglasses/Oty
both Quints
Phase Shield
both Steals
Druid
four Towers
Working on the towers right now. One problem I often have is not enough pillars out early, and I end up wasting sundials at the start without light quanta, and having to discard. This deck has a lot of medium-cost cards, so if it gets a slow start, it gets clogged fast.