Playing with three friends yesterday night and ran into a issue with the Necromancer skill Blood Sucker. Both my character and Ifan could not heal from Blood sucker when casted on blood pools. However my character would cast Blood Suckers and have absolutely nothing happen, but when Ifan casted the skill it would at least suck up the blood from the map just no healing. This wasn't happening until the latest hotfix, so I hope this helps you find the issue.
