As a Necro your HP is your Mana. Furthermore, you don't want to be too soft when you get to the high end and need to be able to take some hits to tap tank if things go bad for you.
First, I'd say don't be a DE Necromancer. Be a Erudite as things like the Mantle of Souls is right there for you when you are higher level (+75 Mana, +10 INT) and a harvester easily fixes any vision problem you may have. Furthermore, the game gives you all sorts of Erudite Necromancer only items like that and the Flayed Skin Armor in Kunark which is dirt cheap because only Erudites and Humans can wear it.
Be different. Be a human, erudite, or at least a gnome. As a Dark Elf you can hide and have night vision... But, as a Erudite you can focus more toward HP and you naturally make up for it with the ridiculous INT.
|