An intial try at a Pythium strategy guide

[PDF]

I made a few test runs, Ethereal Elephants aren'that good, their ever-crappy morale makes them rout pretty easily even if Ethereal . Hoplites are a better choice.
Apart from Pythium and Arco, a good Ethereal candidate is Abysia, with their strong, human-sized infantry.
Beware Etherealizing Nature blessed troops, the regen effect is nice but you also get Berserk, and it makes units charge uncontrollably.. Bless them after the mages are finished with Body Ethereal !