There's no such thing as a truly uncounterable deck.
Quite true.
Even Nova/Tower fueled Protected Shards of Void* are can be countered via Silence/Stone Skin and that hypothetical deck sacrificed so much to avoid direct/indirect card counters that it has a tough time vs AI0(when assuming it is under quanta denial).
I need to go try this now.
And then you get into strategy based counters(out rushing/out stalling/out comboing).
*4vj 4vj 4vj 4vj 4vj 4vj 77i 77i 77i 77i 77i 77i 7jo 7jo 7jo 7k0 7k0 7u2 7u2 7u2 7u2 7u2 7u2 808 808 808 80a 80a 80a 80a 8pt
Edit: Ok, maybe it still has an easy time vs AI0. But the point still stands.