Sipping Demon (Su)
Source: Advanced Player's Guide, p. 111
A 13th level, a hungry ghost monk gains 1 temporary hit point each time he hits an enemy with a melee attack. The monk gains a number of temporary hit points equal to his Wisdom modifier when he scores a critical hit. The maximum number of temporary hit points the monk can have is equal to his monk level. The temporary hit points disappear 1 hour later. The monk can only use this ability when he has at least 1 ki point in his ki pool. This ability is a proscribed manipulation of ki considered by many good monks to be a corruption. The ability replaces diamond soul.