I just lost to Girlsgeneration's deck. She's playing SoSac and poisons in platinium.
I got a death card, so I built one too, and trained against it with different decks (with Purify). Lost 100%. So far, I have 3/0 today, I'm sure I'll have good results.
You can't do anything once the SoSac chain is launched. That's what's problematic. You just have to play during X long turns while doing the opposite of what you deck is supposed to do. Being passive. Waiting. The opposite of fun and combative.
You have absolutely no card that can counter it. Stacking Silence won't help (and you can't afford to have a bad deck in arena if you want spins), nor is whatever has been proposed here (holy lights, antimatter, etc). It's unreliable and not enough.
I freeze my units, I eat them, but while I'm trying to manage my damage output, I'm dieing. Even with tons of heals (again, I can't have a crappy deck specialised in SoSac because I'll lose to everything else in Arena). I don't know what to do. I don't see how I can build a competitive deck that can handle that. Maybe I can try to deck out it... how great!
Maybe a nerf is needed. Maybe more cards are needed, cards that can deal with SoSa. I don't know. But for sure, it's UbberOP as it is now.
(changing the cost is a good start, but the global issue stays the same)