At some point in my last run, Crits stopped doing damage. Fortune would build up, but instead of critting, my attack would simply pass through an enemy. Affected light attack and Lugh ult, making my ult basically pointless. Did not display damage numbers, simply failed to do anything. Really blew up my run.
Log shows NullRefExceptions related to marks. I suspect something that upped my light damage somehow broke the crit on it, but I'm not really sure when I stopped being able to crit. I really suspect it was the buff from the little portal realm areas. Gave me like +40% light damage, -25% heavy damage.