1) Posts of the form "What in the **LL does this do???" do not make it more likely for you to get a prompt answer.
2) Ardent Faith is a lot more useful than Ironskin ever was or is. It makes negative physical effects less detrimental- they don't adversely effect you as much as they would other people.
3) It is by design that it costs a lot of mana for a temporary bonus. It probably is not something you want to try to maintain at all times, but rather something you will use as preparation for opponents who rely on the kinds of abilities it is useful against.
