I don't know anything about vampiric assault besides the fact it's a life stealing GW:EN skill for the sin. However I can assure you that Nightmare Weapon is nothing to fear. I have two rits, and a r/rt and I mainly find it most useful as a offensive heal on my splinter barrager in PVE. Plus it only works for 3 attacks which a sin could burn through in a few seconds. In which 42 per hit is the max if rt is a secondary, but this skill also has the damage reduction.
It is a good source for a quick self heal, although you still have to put yourself in harms way to use it. I can see how a sin might be able to take advantage of this, but if you are implying that this skill should be nerfed I must disagree.
Also with Generous was Tsungrai, it's a decent self heal, but you also suffer the energy loss from holding the ashes. I don't have a sin, but I don't think they have that much energy without dedicating their insignias, runes, and inscriptions to it. This build could be countered with a mesmer, or necro, or better yet, a me/n. That's just off the top of my head.
From my experience, unless a sin attacks me from the shadows, if I see them first, I can "usualy" take them out with SV, and Empathy. That's not including the other 6 skills on my skill bar. With this build you mentioned maybe throw on spirit shackles so they don't have enough energy to heal.
Yeah it's not that creative, but it works for me. It's not an auto win button either. I mainly pvp in FA, and from what I recall since I havn't been there in awhile, sins do have a spell, or form, that can make them immune to spells for a period of time. I could be wrong, but I remember trying to target a few sins before that I just couldn't cast anything on.
Anyway I got kind of sidetracked here, but I still say there isn't that much to fear. If they didn't nerf touch rangers, then I see no need to nerf this. Also yes, I don't play a sin. I don't have the patience to look for groups with one.
