Aqua Regia

Aqua Regia is Hell's favorite drink, a mixture of red wine, ??? and angel's blood. Hurts so good going down. According to the bottle label it's 190 proof and 6.66% Angel's Blood. What’s that you say? The percentages don’t add up? That’s Hellion math.

IRL aqua regia refers to a chemical compound, nitric acid hydrochloride, which can dissolve the noble metals gold and platinum, hence, "royal water" or "the king's water": https://en.wikipedia.org/wiki/Aqua_regia