Your right i was thinking 7 multipyer, since somewhere on forum i saw screenshot of 24K black hole and i just wandered how d hell they managed it.
Solo 1 BD hm . . . doable i think. I have some old save with ghost armor, leather dress, chaos crown and 3lvl medal, and had 82% astral ressistance. But why 1 Bd ? No beneficial spell - cant get medal for ressistances - lower overall available astral ress. Only way to heal him is Gizmo as i can tell. Cant cast Illusion so only way to kill units is to pick places to hit weak unit and some stronger behind it, and w8 for Rain of fire to reset. It`s hard challenge i agree, but prety boring.
Wouldnt 1 Red dragon be better, since you want to test overpowered orcs, just dont use divine armor. Get 3lvl medal for resistances, for healing use only gizmo (when you get it), and for mana regen there`s Magic spring. To match BD magic ress there`s always magic diploma/mage`s cape for 25%/30% so it will be almost the same.
Solo 1 dragon is tough for sure. but it`s also so monotonous
I`we read here for EGD inisibility and heavy use illusion spell, for RD stone skin and also illusion, for BD never tried but i guess it`s like i mentioned above fly around , kill enemy with spells and rain of fire.
For paladin hero/paladin unit it would be tricky for sure. But for Paladin class, your Prayer ability and ressurection would be stronger 30%. And basic 30% physical/magic ress and 10% fire, and morale is easily on +2. As you said infinite repair is life saver for droids, and for blackies imba evlin is in no way connected to int of hero, you get 30% revived units no matter do you have 1 or 80 int points it`s such overpowered spell. So lets even things up a bit : 18 fights for solo paladin run (4 more since droid run you skiped 3 fights to get imba Axe of ice 3lvl), So fights could be : Battle academy (to get Holy armor skill), Tomas Torkve (for sword obviously since both droids and blackies have free -leadership% item available), Driller (for his namesake weapon and to fix difference in droids no retaliation bonus from axe) and last fight by your choice, but no Frog or Spider (since they give to high exp boost). This fights would help out with Purifier medal. I would try this myself, but my kiting skills are pretty low