I really don’t see an issue with reapers what so ever. The only thing the new “elite tree” did was increase our survivability with healing via shouts/boons and make necros a stronger condition based class. Which with the raid coming out when ever. is very much needed. The build I linked was merely a hint on how the new elite tree can be used to help assist the melee side of the spectrum with also trying to maximize the use of necros life siphon.
The issue is that bb gave us a way to finally heal through DS/RS. Entering shroud while at low health has always been a double edged sword, doing so might save your life but also you just missed a large heal coming from an ally ele. Then shroud runs out and now your still massively hurt but before someone can heal your or you can heal yourself you get killed. bb was a way for us to finally survive times like that, allowing allies to provide us healing through shroud via buffing us. Honestly an icd from ally boons or even something like “regen now heals through shroud”, anything other then a full cut would have been better.
Now let’s touch on you’re build. You wanted to " maximize my vulnerability stacks asap to be the sort of “team player” and also keeping wells and the new “buff(not really nerf)” to Blighter’s Boon. So now I have high survivability with my damage."
Maximize my vulnerability- you can do that with this build. I would change a few traits, like grabbing rending shroud. Sadly in party senerios, a five man no necro party can sustain 25 stacks, and come 10 man raiding, a dedicated vulnerability man will be pointless.
high suriviability, where is that? blood magic for the vampric wells and presence? the wells only leech life for you and the protection is negligible compared to guards or other classes. and you have traded out soul reaping, meaning a major debuff to your shroud functionality, specially the loss of death perception. you attempt to remedy this by adding berserker armor with a bit of cavalier which leaves your with small <20k hp pool and a smaller shroud pool also.
Your damage possibility is solid with high power and ferocity but that is what reaper is meant to bring to the table, a damage dealer. only issue is your strapping it to the frail light armor of a necro.
In conclusion the vulnerability would not be missed,
your glass cannon build could be traded for something like a shudders full, zerker, warrior. he would have the same hp pool, minus shroud, but would be able to benefit fully from team mates which could apply heals to him. better yet he could provide better team help via banners or phalanx strengh. he can even provide himself with sustain/life saving moments via skills like endure pain.
tl:dr
My point with all of this, reaper was a specialization that was advertised as being this deadly juggernaut who didn’t burst his enemy to death but was a slow and steady death, who was comfortable fighting more then one target as it just made his RS1 and shouts more powerful.
Now Anet has gutted the trait that made reaper into what they sold it to us as. All we have left is to go onslaught and fill the dps/zerker roll in their new “non-zerker meta” they have been pushing. As we can’t be a tanky class, and everyone is better for supporting.