Amplify Damage seems like such a no-brainer given all the Druid's pets (except the Poison Creeper) do only physical damage. But, the Raven's Blind overwrites Amp. So, I'm wondering how to deal with the many PI monsters in Hell.
Well, I could have figuered that one out on my own. But, I often play the Eastern Sun mod which provides bonuses to other summons depending on the number of points you have in Raven. Plus, you can have up to 8 Ravens from hard points, and for every 5 points you have in your other pets, you also receive an additional Raven. So, at least in this mod, Ravens carry more importance.