[DrPraetorious]

This doesn't look feasible to me.

There are similar features in the game now - more maenads for turmoil, for example - which are mostly hard-coded for an individual scale/unit combo. So they might hardcode each of the bonuses you propose, but a mod script to add bonuses of those kinds is pretty well impossible.

I particularly like the phoenix making the prophet immortal.

If they were going to do a dominions 4, it would be nice if the various data structures were handled more dynamically so that this kind of thing were easier to do. But that's highly unlikely and would require a rewrite more or less from the ground up.