Getting the most out of Parasite

As last decision- you can invest in iceclaw totems. They're awesome against single target.

Craft weapon with belefire proc.

They can be decent against single target, but it's not immediately evident how. That's probably where the notion comes from. But that's only the case because it is a natural weak point of the spec. I mean it wouldn't be terribly balanced if they just facerolled everything right out of the gate, would it? Every spec has (and should have) a downside, and I don't think it's terribly controversial to admit that single target is that of melee necros.

Before I lost my old saves, I had a setup with a dagger/shield that managed to be pretty decent against single target with just parasite. Melee necros with dagger/shield are underrated, imo.

That said, my old unholy Paladin with Malthael's set outclassed my melee necro in just about every way, so I stopped looking into min/maxing this particular build. So... yeah, there very well could be ways to make them top tier in terms of single target DPS. If you know how, feel free to share your approach (and/or build) and put this misconception to bed once and for all.

Another question, does %EWD affect parasite projectiles? It doesn't seem to affect tooltip damage.

sure it does

Ah, you're right. The difference was so small that I assumed it was the same number. How does %EWD work?

like TCD, formula is in LFAQ in docs

I've read it, but I still don't understand why EWD seems to have such a small impact on my DPS relative to the investment.

Because of the way the formula works. EWD is only effective if you have high base weapon damage.

Also bear in mind that the more EWD you have (i.e. smax deathlord and full str build for example) the less and less of an increase in char sheet damage you will get from 1 EWD orb for example. Why? Because maths. Linearly increasing stats always give diminishing returns. I.e. Going from 100 EWD to 200 EWD will be a lot more noticeable on the char sheet than going from 1k to 1.1k.

E: That being said, EWD weapon orbs are almost never worth it (especially for a build like melee necro who gets EWD from skills) since they have to compete with %ED, max dmg, Life leech, life after kill, crushing blow etc. If you could get them on any item and not just weapons they would be used a lot more.

That makes sense. Kind of like in PoE, each successive life node matters less and less.