Agent of the Grave's Lich Touch Question

[Theonlyjanitor]

http://www.d20pfsrd.com/classes/prestige-classes/other-paizo/a-b/agent-of-the-grave

I was wondering what kind of action agent of the grave's "Lich Touch" ability, is, It says it's an attack, but is it a natural attack or just an ability? Can it be used in a full attack? Can it be used more than once per round? The ability is really vague.

[TuggyNE]

It's an Su ability, so unless PF changed it, it defaults to a standard action to use.