As for Jitan's killing - he casting lifeblood on striking so you need high defence or very high dps. For necro i was using frostclaw totems for him since it deals great damage to single target even at 1 point.
I'm actually doing some intense calculations right now like polynomial regression on skills to make it easier for comparisons and such, but so far idk.
How do multiple sources of flat poison damage average out their durations? Say I had sources A,B and C. Is it the average between A and B and then average between A&B and C so it's (A+B+2C)/4? or are they all averaged simultaneously so that it's (A+B+C)/3?