This AA costs 12 points and becomes available to the appropriate classes at level 59 on the Class tab in the AA window, after having spent enough points in the General and Archetype tabs.
It allows the caster to cast an unresistable charm on an appropriate mob type up to level 46, as long as the mob is not uncharmable. The ability has a 72 minute reuse timer, which is one game day. The pet buff box shows the duration as permanent. It cannot be dispelled, but will break with hide or invis.
This AA first came out with Shadows of Luclin when the level cap was 60 and AA were first introduced to EQ. It has gone through some changes since then. It used to not quite be permanent, but last several hours. It used to be dispellable, which was a real bummer when using a DC pet to farm in areas with dispelling mobs.
After the level cap increased from 60, this ability lost a lot of its usefullness. Every Planes of Power zone had a DC'able mob just to appease those who had the ability, but the pets became less and less usefull and in later expansions DC'able mobs were left out of high-end zones.
As added worry-free DPS for druids or enchanters with summoned pets that do less damage, this AA can be "somewhat" handy, in zones that have an available mob. Most people fly past the levels that it would be usefull in though, and then have higher dps pets available so don't need to buy this AA. It is, however, a prerequisite, for enchanters at least, for higher level unresistable charm AA Edict of Command.
