Sorry to be of a bother, not sure if this is a bug.

Skill: 'shadowdrain' modifies moves by -29 for -1 hours.
Skill: 'shadowdrain' modifies mana by -29 for -1 hours.
Skill: 'shadowdrain' modifies hp by -29 for -1 hours.
Skill: 'shadowdrain' modifies moves by -27 for -1 hours.
Skill: 'shadowdrain' modifies mana by -27 for -1 hours.
Skill: 'shadowdrain' modifies hp by -27 for -1 hours.

After real life hours like 4 hrs(online & offline), after trying lay hands & acolyte power altruism, doesn't seem to heal it. Seems to stack indefinitely.