Mictlan

[Graeme Dice]

DominionsFAN said:
Hell even the national troops should stand a chance in the endgame.

If national troops, which require absolutely no research, are still viable when level 9 spells are being cast, then you have a bigger problem with game balance. That problem being that the research wasn't worth the cost.

I meant to change a specific summoning spell like 1. to summon an other monster, not the original one. 2. give the spell a new required level & gemcost]

Have you ever even read the modding manual? Everything you describe is already possible.