The spell Body ethereal

[Boron]

body etheral is alteration 3 .
alteration 3 covers all buffs needed for vq for indy killing .

that makes pythium a great early game expander .
some theurgs / theurg alcolytes + principles .
as pvk said 4-5 such mages with principles on hold order are enough to cover at least 60% with body etheral .

so pythium can easy take 2 provinces / turn from turn 5 on .

you could as a variation put 2-3 S on your vq . because she is poison immune she can then body etheralize hydras . or you completely screw the vq sc build and give her high astral magic instead for mind duels + astral supporter

unfortunately serpent cult is because of its lack of astral magic not a viable choice
otherwise serpent priests + hydras + bless would rock .
but astral magic is the crucial element in my early game pythium strat .

[Lex]

having the spell only affect an adjacent square is not so bad. If you order your fighters to hold a turn, any flyers attacking your rear will find your casters embeded in your army and will be cut down in short order. Also definitly leave buffer troops up front to attract enemy fire. Staff of Storms is a must, and missile protection, if you can afford to mass produce the items, could let you try more daring tactics. Once your troops are buffed, your casters can always fall back on Stellar Cascades to prevent enemy cavalry from rushing past your army and taking out your casters.

But I've found each path can be really powerful when you group large numbers of casters in combat. Astral is no exception.