but what is he drinking ? :o

that's a very unfortunate question, because it triggered a completely uncalled infodump in me :D

long story short, it's brandy. definitely looted after some battle ot something like this, because it is considered a luxury (basically, only magi order alchemists have access to distilling equipment, and demand for strong alcohol in the land easily outmatches the supply) and Medar is at his lowest in this point of time and surely can't afford to buy it normally.
it is usually consumed watered down and with some honey added, but Medar isn't even remotely a person of refined taste and just drinks it as is.

sounds fine to me, i also drink brandy as is ! silly alchemists keeping all the good stuff for themselves though :o

i assume that they are less advanced distillers than the modern ones, so their stuff is far rougher on the palate xD (haven't really researched brandymaking too deeply tho, so mostly was using early rum history as a reference there)
and well, mages are very much fine with this situation, it makes them a good influx of gold after all x)