Demon army warrior on hard with no loss?

[Infiltrator]

Well, since my old thread about Necro warrior got concluded with the sad fact that undead can't be ressurected easily, I shifted my focus towards a similar strat that I used to beat KBTL with.

I'm lvl 12 atm, no losses yet and about 70 battles in, got a black dragon (soon to be 2), Succubi, Demons, Executioneers and Demonologists. So far I can easily win with the Demon/Demonologist summons serving as meatshields and landing the Blackie nearby to be the off-tank.

Even heroes tend to focus on the summons.

But can this be done no-loss style with super bosses? My only way to bring back lost troops is the Demonologist life drain or Ressurect (which is shitty at least atm considering I'm a warrior).