The tactic can be found here. You have to scroll down alot to the dark rites spec section.
http://warhammeronline.wikia.com/wiki/D ... _abilities
This is a morale pump tactic.
The tactic reads as:
Restore essence will also grant 250 points of Morale to your ally.
This tactic was used to get dark rite Dok's to their morale 4's 1001 dark blessing which used to have a 30 sec duration, which can be found on that same website page.
The trick at the time was to run 2 dark rites dok's running that tactic and morale pump 1 of the dark rites dok's to reach their morale 4 very fast. Then you'd start the cycle.
You could have kept using the trick throughout the fight for 100% upkeep of 1001 dark blessings.
This is how Dark Elves racial group got their resistance/armor buff.
This was deemed too powerful at the time and taken away. It was thought of as a exploit by the community. I think it was by design for these racial groups.
High elves still maintain their morale pump trick with bolstering boon tactic. Below is a bolstering boon trick I was talking about in a high elf centric 12 man post.
Spoiler: