How to fight Ashdod

[LDiCesare]

I suppose the bless is something like E10N4+ and his adonim are the main issue?
Definitely use magic duel against all his astral mages. There are many. It works quite well and one third or one fourth of his mages will be rendered unusable against you. Teleporting a magic dueller (who may return after committing his deed) works well. Best if you have a high level astral pretender. It looks like only Ermor could pull this easily out of the three of you, though, unless you picked an S pretender.
Try for fatigue spells. Cold auras may work as water is about the only thing Ashdod is lacking.

[Galou]

Increase unrest (100+) in his capital with Hurricane (you), blight (shinu)(cast a lot in one single turn and maintain the unrest with some other casting in the following turns). This way he could not recruit more of his sacreds until he cast a dome and patrol a lot his capital.

Use your Vans for raiding his territories...Ashdod's troops are all but cheap.