Hello! This is such an interesting subclass! I love the tenets (though gods do they seem difficult to uphold) and truly exemplify what an avatar of justice should be.
I really like the choice of spells as well, and Avatar of the Law is extremely powerful (as it should be!) and brings a combination of combat/utility that I find cool, because it gives a chance to use this power outside combat. Stand Trial seems like it might be a bit too powerful if your PCs have ranged spells because they cannot save at all apart from the first time, and ten rounds will kill practically everything. Maybe that should be reconsidered.
Anyway, thank you <3