Epic War Age (EWA) - Adapted Mod Collection

How does he reproduce? Are there specific conditions, and what changes cause him to appear?

Simply delete the file profiles/autoexec_a2.cfg
I haven't looked into what specifically needs to be changed in it to achieve this effect yet.

Update: I found the line. It turns out, it's not a bug, but a feature :D Although it's practically useless.
Change combat_force_average_arena 1 to combat_force_average_arena 0, and that's it.
And yes, it works with Eternal Essence if you don't delete the file, but instead change the line.