As of now, there is literally zero point in putting more than 1 skill rank in Revive. Yes, higher ranks lead to lower mana costs, but enchantresses aren't generally worried about that, with their high mana pools and regen rates (maybe "paladin" builds care a little bit more, but potions are cheap compared to skill ranks).

Suggestion: Make each skill rank restore the revived characters to a higher health and mana. Say, just for the sake of example, 20%, 40%, 60%, 80%, and 100% of max at the five ranks.

In the heat of a big boss battle, not requiring your allies to "pot up" after a revive might make it useful enough to at least consider spending an extra skill point or two here.