New to Necro
All I can help right now is a power build with GS from Hollts, maybe check his channel in youtube, I find it really helpful.
We’re all mad here…
http://metabattle.com/wiki/Build:Reaper_-_Signet_Chillomancer
IMO this is the strongest PvP build out there for necros currently. It gives you the tools to deal with any class, and does great hybrid damage while being pretty tanky. As far as weaknesses go, nothing class/build specific just 1v2s vs burst will wreck you (such as thief dh) combo. This build can beat any class in a straight 1v1. Swap last trait in soul reaping from dhuumfire to the 50% crit chance in shroud if youre up against multiple tempests or heavy condi clear.
http://metabattle.com/wiki/Build:Reaper_-_Corruptionmancer
This one is a more condi heavy build with better burst if using wanderers amulet. Mobility kinda sucks on it though, so using flesh wurm is recommended on maps like kyhlo and temple. I also like corrosive poison cloud if you are a fan of teamfights. With cpc and reaper shroud 4 you can stack around 30 poison stacks on a group of enemies. Probably the best condimancer cleave available.
Weaknesses, mobility, sustain, and tempests with diamond skin (especially if using wanderers). Positioning is insanely important with this build or youll be bursted in seconds by a dh.
General advice for necros. You cant rely on invulns and quick escapes anymore without a wurm being pre placed. Dont just rotate through staff marks, many new necros do this to their detriment. Staff 4 and 5 are two of the best skills in the game if used properly, especially vs condi burst cheese. Pay attention to enemy boons, conversions can instantly change the fight in your favor. Lastly, never engage in losing fight, such as running to help a 1v2 when your ally is almost down, you wont be able to run away and its very tough to power rez in that situation as a necro.