This gem increases damage done with all Primary skills of any class, stacking with other enhancements: damage increase is multiplicative with most similar effects. This includes Signature Spells of Wizards and Witch Doctors. Upgrading increases the damage bonus.
At rank 25, it also causes each Primary skill to heal the character for 4% of maximum Life per cast (not per hit), regardless of the attack's Proc Coefficient, as long as this cast hits at least one enemy. For most of the game's Primary skills, the healing can be considered as Life on Hit, with the additional function of working on breakable objects. The gem may prove most useful to exceptionally fast attackers, like a Barbarian using Frenzy or a Monk using Shenlong's Spirit. For Electrocute, one cast equals two consecutive zaps. Siphon Blood, the only primary channeled skill, will trigger this effect once per tick of damage.
- Increases the damage of Primary skills by 25%.
- Upgrade: +0.5% damage bonus per Rank.
- Primary skills heal 4% of maximum Life on hit. (Requires Rank 25)