Ranking up was harder at higher levels because wizard bodies tended to be corrupted by mana over the years, and while potions could help negate the effects, they did possess side effects of their own. Mana corruption and the damage left by potions would pile up over the years, causing all sorts of minor harm to the bodies of the wizards, which, in turn, would create technically irreversible harm.
So the "light healing potion" Abel took out was meant to target injury. No, he couldn't use it to treat internal wounds. He had to use the ones he synthesized with his Horadric Cube for that. That was the reason he had the "light healing potion" out here in the first place. As for the red one, that was meant to aid bodily recovery so the healing process could be done in a more precise manner.
Wizard Hal spoke to the two archpriests bluntly, "If you have something to say to Master Bennett, please be as direct as you can."
