As I stated elsewhere, I think that the corruption needs some beefing up.
In the original Symbaroum you could very quickly (a little too quickly) turn into abomination, while in here it's rather safe to go beyond your treshold.
I'm still planning my first test game, so the rules as written might make sense, but for now I feel like there is serious room for improvement.
Page 38: Corruption
Marks of Corruption is rolled when you go above your corruption treshold. As long as you keep rolling more than the target, you can go pretty high beyond the treshold without any ill effects, and even if you roll under it, you don't get any permanent effects, unless on a roll of 1 or 2.
I think that the higher numbers need some serious work! You can only get 20 as a result if your corruption is at least 20 points above your treshold. That should always be very serious, no matter how well you rolled. I'd say that there should be very real danger of losing your character on results 15 and up.
I'd turn the table upside down, where results 1-5 are mildish (mostly hideable appearance changes + change to your shadow), 6-10 are more serious (taste for raw meat and cadavers etc., plus your shadow now shows serious corruption), 11-15 are really bad (one point of permanent corruption + very visible marks, like black eyes, split tongue, tentacles, shadow now very dark), 16-19 are horrible (one or two points of permanent corruption + random acts of terror and very public displays of corruption, shadow now black), with 20 you turn into a blight born! This way you would gain more and more marks and errational behaviour, if you don't stop in time and you would be put down before you have a chance of turning into abomination.
Each time you get more corruption you need to roll, as long as your total is above the treshold. And of course any result you rolled shouldn't reduce your current corruption, but you need to rest and do some cleansing rituals to get rid of it. Of course if you are at 10 over and get 2 points to go to 12 over you only roll once, after you have taken the point of permanent corruption (so rolling against 13).
This is not the best either, as both very low and very high rolls (as long as you roll above the treshold) are fine and only the high numbers below the treshold are really bad.
I could even go so far as change this completely to D6 based table: Roll a D6 for each point above your corruption treshold. For each 6 rolled, add another die...
Keep the results of 1 - 10 relatively mild but go to very bad effects past the 20 mark. This way you could make some nasty tables and the players would FEAR the rolls as even one rolled dice could be a 6 and then you roll another which could also turn out to be 6...