I would love to have more fluff for this class to explain what's going on with it. It's an interesting concept (I like the idea of doing a more defensive / transmorphic class), but especially when it comes to the archetypes it seems a little muddled. I don't really understand how those tie into the class itself. I think settling the class's identity would help in determining where to push it.

A few comments on features:

Divine Body seems fairly strong at some levels you can access it, and I almost wonder if the capstone shouldn't just be unlimited use of it.

I think more of the offensive features (save the built-in ability bonus on DB) come too late as well and should be spaced out. Perhaps give more uses of Divine Protection and permit them to be used on offense as well (somewhat similar to Bardic Inspiration, I suppose).

The archetypes probably have too much of the power budget for the class, which makes balancing them against each other quite difficult and more work into doing class archetypes.

I think the class as a whole is a bit heavy on the combat side--can there be more utility / exploratory type features built into the base chassis at lower levels?