Inferno tactics.

This way, you can immediately replenish losses during battle, especially for lower-level troops.

It's not advisable to transform Cerberuses into demons; it's a quite useful monster...

That is, we cast an expert fire shield on the demons and teleport them (or just move them) to the very back, without worrying too much about them.

Next, we use the "sadomasochists" and in one turn, without any worries, resurrect all the demons.

It's better for the hero to focus on improving defensive skills.

I think the following heroes are good: Nimue, Xiron, Qsarr, and as starting heroes, Kal and Octavia.