During the second battle with the black sphere and armbands, I was expecting Armageddon and prepared a counter-Armageddon with CM 33, which would kill both, but unfortunately, the opponent's resistance triggered specifically on the black creature stack. Thanks for the game.

Sorry for interrupting, but it wasn't resistance.

It's the mechanics of how the black sphere works. If you're wearing it, your Armageddon hits the opponent's black dragons, but the opponent's Armageddon doesn't hit his own dragons. You CAN apply slow to the opponent's dragons, but he can't apply haste to his own dragons.

Therefore, the initial assumption that with the black sphere, the opponent's Armageddon damages both of you is incorrect.

All of this is explained in the physics guide.