Inferno’s main forces.

I think that Inferno's main strength lies in opening portals. If you play for a long time, you definitely need to upgrade Summoning. Then, you can cause a lot of trouble with a small army. If you don't upgrade Summoning, you need to make sure that Nightmares and Dogs reach their target in one turn, blocking it and attacking, because the strength of demons lies in their attack. And instead of the killed Nightmares or Dogs, you can summon Pit Lords, which are more durable and again, block archers and take the hit. Demonesses can enslave someone, and then you can attack them with the opponent's army, negating retaliation, so that your troops can attack normally.