The tactic isn't quite right. You enter the final battle with Immortal items consumed, right? Let's say you have 5 heroes, Titans, and Nagas. So, how many Immortals can you steal? Correct – 2. And the rest will remain intact on their owners. Of course, according to Murphy's Law, they will be removed from some weak runner or pathetic mage. That's how a strong, fast Haven hero's turn is wasted.
Why 2? Based on the number of creatures? It seems like all beneficial effects are removed and randomly distributed to friendly units, and several buffs can be applied to one unit...
Isn't that right?