I think max health reduction sounds awesome but is one of the most useless skills. Usually the heroes that have this skill suck unless they have another key skill like “mindless attack”. Copying from what I said in horus’ thread:
When you go against him on defense, the max health reduction does look scary on the HP bar. But the chances it actually affects the outcome of the battle is so slim…say the battle is going badly, your heroes are at 200-400 hp. Max health reduction isn’t why you’re going to lose. It’s likely only stopping you from healing your heroes past 1000 hp…and otherwise has zero impact