We are pushing the hit-and-run strategy of the Academy.

I tried using Keen Intellect combined with a counterspell. The opponent lost and is now also leveling up Keen Intellect. And since he's playing as Orai, the stone falls earlier, and the opponent manages to escape before it's destroyed.

As I already mentioned, the key is to anticipate. If Orai has Keen Intellect, without Battle to the Last, not only will they not provide defense, but you also won't gain enough levels (and there's still Chaos and Sorcery to consider). So, unleash your anti-hit-and-run unit on the enemy: 6 stacks of Furies (for duels before casting) and 1 Chaos Dragon (for a powerful stack after casting). Of course, if you scatter Golems across the stacks in random quantities, things will get interesting, but without Battle, Chaos Dragons start to dominate.