Here's a quick summary of the Blessings in Dom II:
The Blessings given to Sacred troops in Dominions II vary based purely on the magical power your Pretender starts with at the beginning of the game. The Blessing effects are locked-in when the game starts, and no matter how your Pretender changes, the Blessings will not be altered.
There are two tiers of Blessing effects. The first become available with a power level of 4 in a given path, and each path has its own individual effects for both tiers. The first tier powers grow in effect with additional power at a rate of either +1 per 2 levels or +5% per level, depending on the nature of the Blessing.
An example of a first-tier Blessing is the +1 to Magic Resistance you get from an Astral power of 4. The highest power you can take in a path at the beginning of the game is 10, so you can theoretically get a +4 MR from your Blessings with Astral 10. Another example is Death magic's Lesser Fear effect.
The second-tier Blessings are unlocked with a power of 9. Astral magic of 9+ grants all your Blessed troops with the Twist Fate spell, protecting them from the first blow that would otherwise have injured them. Fire magic of 9+ gives your Blessed troops exceptionally powerful flaming weaponry.
There's also a Morale bonus on top of any friendly Dominion bonus. I'm not sure at the moment how strong that bonus is, but I'll post the detail once I have the chance to check on it. Pretenders who don't qualify for any of the other Blessing effects will get an additional +3 Morale bonus.
I've been finding it a very flexible system. It adds a lot of variety without any micromanagement. The objective of Power 9 may seem rather high, but the benefits are also rather high. I usually design my Pretenders to have one path of 9 or 10, backed up with one or two other paths with powers of 4-6. The variety of Blessing effects I get from that really show on the battlefield.
Another variation is to take level 4 in as many paths as you can. The Blessing effects will all be of the lesser nature, but they stack up to a great potency.
There's a lot of room to experiment and design. I predict there will be many debates launched on the best Blessing schemes for various nations and Pretenders in the upcoming months.
(Oh, and I'd like to know about the transformation effects too. There are many transforming Pretenders and units, and I'm curious how the math works. I think Illwinter will have to answer that one directly though.)