The necromancer build problem about symptoms
I can see that english is not your fist language from the errors in the translation program you are using, but I will provide you with a link to many good builds available for people interested in playing a necro in wvw.
I use this build on large wvw events (zergs). It is called “The Abomination”:
http://gw2skills.net/editor/?fQQQNAodWjMaV6haea87JAZGY/80DuHXc4D5C-jwxAoLioRyBIFaIaZvioxWOLiGryGT9SEVLEggxA-e
It is easy to play. See this guide (he talks it as pve tanking build, but it works also in WvW): http://youtu.be/y_bIqwtB-fw
Because it is tank, it is good for capping and front-line tagging. Build supports other front-line persons with stability, protection, blind via wells. Plague gives blind or cripple if enemies try to escape.
My stats on LA (30k normal HP, 50k plague HP)