Agree with Cleveland and Micah. Though I would prefer him asleep and pick up speed after Construction or Alteration is researched (but just maybe Black Steel Plate could be enough at the start).
Considering paths I would avoid Astral unless there's absolutely no other way to get it... but usually there is. Nature may be good but will require N4, which would also give bless (if your sacreds would benefit from such) + the above-mentioned E2+. What is beautiful he can actually pull that off if asleep.
I also agree that Cold Dominion gives him an edge - so he can be better for nations which are Cold-preferring. But this is a minor consideration.
Considering a Growth - it's easy! You just say that he's an ancient Druid leader or former sacrificial Fertility king!