I have the skill, see the floating text pop but can't see that anything's happening. Is the skill working? What is it supposed to do? I thought it was a weak man's life drain, but so far...Nothing. Please post your findings, it may be bugged. EDIT: Hmmm... It seems it's purpose is to give a proc based mana gain chance per hit, beyond the original mechanics of mana per kill.
Vital Siphon indeed works. It only procs from your physical hits. On that note, Blood magic seems very powerful. I haven't had to drink once as a Promethean mage on Rogue Difficulty. Monster zoos are a breeze since you never run out of mana by just killing things constantly. The first skills gives 6 mana per kill which is very strong. The negative resistance you receive hasn't affected my hero yet, mostly because I have yet to find something that does righteous damage.
