I would like to add Spirit:
Spirit I gives protection against fear (dragons & demons, eg Hyborem), and it increases the heal rate of your units (useful if combined with march)
Spirit II increases the culture & happiness in a city. Good in a game such as FfH, where there are precious few culture buildings.
Spirit III, for a one-time boost to relations with other players, decreasing the chance they'll attack you, especially good if you are already fighting a war, or if you are playing a builder game
Spirit gives a 5% GPP boost. Useful for any Civ, especially for an Altar victory. It also allows you to build Sironia's Shrine, letting you heal a unit per turn 15% health. Very convinent when attacking.
Life lets you build Aqua Succellus. This wonder is most likely the only source of healing diseases from your highly promoted unit, as the Pool Of Tears only has 35% chance of being included per game.
Mind gives a 3% boost to research. Enchantment a boost to Happiness. Life a boost to Health.
Chaos gives a chance (passively, or with Chaos II) to boost a unit beyond normal strength. A Heroic Str/Defense I unit with a Charmismatic leader gets XP fast.
Law is also useful for decreasing maintinance, and also getting Loyalty on units, before you raise the AC & bring the Avatar of Wrath. Its also the only thing to stop dominating Archmages/Liches in MP
Earth's passive bonus to finding resources is useful in the game, as it allows you to claim that much needed metal, such as Mithril, or get a second one for insurance, or to trade for an exorbatant price
Mind II can be useful for a boost to research. It may seems small, but when you factor in multipliers from buildings...
Earth I can also be useful for an extra 25% Defence boost
Life III lets you ressurect your Civ's Hero. Better yet, you've gained the ability to build the Shrine of the Champion, and have your Hero! And only for one measly Life Node.
You can tell I'm a builder... Earth I, Mind II, Spirit II Mages are really beneficial for a city (+4 Culture, +4 Research, 25% defence, +1 Happiness). And if you give them Air II, they can even help defend versus multiple enemies.
Nature III can be a godsend in some places, as it upgrades your terrain, how you want it. Even if you use Genesis, what about later cities?
Death may seem powerful, but only because it has the easiest & simplist to use spells. You have to remember that you get a -4 relations boost with other leaders who are good, and if you are part of the Overcouncil, you may find your mana disappear...