Necro uses Vampiric Embrace which does 20% life drain, 15% stam regen and 3% mana regen.
Bushido and honoring the target gives you perfection which is a strong multiplier.
Chivalry uses Enemy of One which is another strong damage multiplier.
Honor the target, use Enemy of One, attack the target and use a weapon that grants you the Armor Ignore special and you spam that. You need to have a suit with HIGH stamina, have a weapon with stam and mana leech. Max out DCI and HCI, and add as much SSI as you can. Stratics has many threads on Sampires and Suits.
In a nutshell but this should give you the general idea.
