On live servers DoTs (possibly only lifetap DoTs, I'm
not sure?) do 2/3 damage to players compared to mobs,
and the Necro lich line of hit point to mana spells are
considered to be lifetap DoTs.
As a result, the lich spells actually only take 2/3 of
the hit points specified in the spell description,
whereas I believe that in the emulator they're taking
the full number of hit points: my Eqemu necro seems to
lose hit points significantly faster than the same
character on a live server.