I have not progressed to the level described in https://forums.elementalgame.com/436496 but I have started to build better opponents for myself.

I imagine other people have been doing so, also.

Perhaps we could build a list of our favorite worthy opponent builds -- builds that the AI knows how to play?

So far, for me, my consistently best opponent has been:  Take Oracle Ceresa's build, downgrade her staff to a war staff, replace summoner with warlock, replace water apprentice with fire disciple, and replace scarred with cowardly.