This spell is one of the most useful AAs you get.
The original line is Ancestral Aid series from Omens.
This AA is bought by shamans in the TSS tab. This aa Ability Stacks with any other heal over time spell(excuding if it was casted by another shaman) and union of spirits.
This AA ability is Instant cast, increases your group stats a little, and of course heal over time what could you ask for more? Well it works with TGB (Target group buff) and theres no level restriction on who you cast it on (Castable even on the level 1s!).
The greatest thing is its MGBable, thats right you can MGB ancestral aid, No casting either, you can help your raid by pressing two buttons MGB and Ancestral aid and your raid or people around you will get wonderful Heal over time increasing their life span a little longer.
Another great thing is that Ancestral Aid can HoT crit if you have the AAs.