[Wauthan]

Guess I too should pop in to offer some quick words of advice. I've gone up against Pythium tons of times as they are my friends favorite nation.

Negate their javelins and they will fall. As Zen already mentioned it's a very good idea to make a beeline for those spells that will screw up his ability to use them. Your heavily armoured infantery is resource expensive but a lot tougher than his regular units (as well as very durable against even withering javelin fire), forcing him to forgoe javelineers for the much more expensive Emerald Guards.

Masses of thightly packed infantery means your elephants and chariots will pack the largest possible damage. Group them with heart companions to up their morale and set them to hold and attack behind a screen of Hoplites.

Astral is perhaps the most devastating magic against solitary powerful units. It sucks against hordes though so if he starts leaning on mages, you start churning out the battalions.

Your Astrologers, especially a 4 astral one, can do everything his mages can. Use the Astral assassination spells to take them out without their annyoing communicant slaves.

Your mystics span the full range of magic but are vulnerable to magic duels. An astral assassination spell might also take them out. I would switch to nonastral mages as soon as could find them.

Your priestesses can cure every ailment. Milk this ability for all its worth. Draw him into battle in low supply areas, where you can cure disease but he can't. Toss disease spells at him even if it strikes your own units. Take a moment to rest your armies to cure them completely. While his veterans get chipped away with time yours will endure. Go all out SC pretender to spearhead your armies. (preferably one with high magic resistance) You can always heal it when it starts losing limbs.

He will use assassins against you, if he knows what's good for him, so stick a few bodyguards on your most valuable mages.

Take the construction path if you can. Constructs are immune to most of the things he can toss at you and pretty cheap for their punch. I remember overrunning Pythium completely with massed Lumber Constructs but that was a stroke of luck I must admit. Nevertheless it helps your armies if you can stick a few golemlike beings in the front line. You got cheap laboratories so healing them is no problem, especially since your priestesses are also skilled greasemonkeys.