Negate and battle winner I can use every turn with Eternal Covenant? Yes please!
Well, you can't do the "Negate/discard" portion if this card is a hero, which it will be if you use Eternal Covenant. But I agree that this card is too splashable, flexible, and powerful.
Here is an alternate idea that I think is toned down enough:
Prophets as Swords7/7 Green Hero / 4/1 Green GE
Identifiers: Prophet, X = number of your Isaiah - Malachi prophets
"You may exchange this hero with an Isaiah - Malachi prophet in deck or territory to make all draw X (limit 3). If your Isaiah - Malachi prophet is opposed, exchange an evil character in battle with one in opponent's territory to discard an evil card in that territory. Cannot be interrupted."