HotA - General Questions and Discussions

But I believe that any, even the most overpowered ability, should follow a clear logic, and not be an ill-conceived, random thing.

It seems to me that it's difficult to accuse the current effect of lacking clear logic. Its description sounds like this: "Reduces the power of the enemy hero's magic by x% during battle." And the ability actually does exactly that, no more and no less. The effect is also displayed accurately in the battle interface (the reduced magic power of the enemy in parentheses). The weakening of your own Armageddon has nothing to do with the effect of the ability or its display in the battle interface, so it seems more like something done "randomly."