It is an interesting win condition isn't it?
It's basically saying I'm owning you so badly I mind as well win, right now
There are a couple counters.
If you get out enough damage it's possible to give the SS stall some trouble, since if it's utilizing Miracle, it can't use Smite that same turn (No quanta to activate). Even with the full set of SoGs and Sancs, since it needs to be activated when you have 4x HP, and they don't heal until after, if you keep them under that range on your turn it's not bad.
Any kind of reusable permanent control would cripple this kind of stall badly, unless it packs a LOT of PAs. It costs a lot of quanta to play and use, so if it gets destroyed it could be potentially really annoying.
If there's ever a max HP reducing ability, that would nerf this card as well.