Edit; there seems to be a lot of redundancy coming in in the comments so I'll add this; Yes there are specific use cases, particularly with weapons without a weapon power option (arts, daggers, bows, etc.) Additionally, I'm not looking at SP costs or any specific run strategy, this purely a hypothetical and mathematic argument comparing one skill to another skill for single slot economy.

Edit2; I guess the real star of the show is reprisal though. I didn't want to get into it because it's dlc locked but as I stated above I'm just looking hypothetically.

Reprisal would give about 1 point of damage for every 3 health you're missing. 3 damage per 10 HP. Reprisal gives 5 per 10hp. 1 point for every 2 missing hp.

Where it does require a unit to take damage, it is indisputably the biggest boost to damage with maximum of 48(?) on a berserker. It's not true damage but it does proc with magic and on enemy phase, allowing vantage to have some genuine use.

This is just another thing that has come along that brings down lunar braces viability, in addition to the well.

Now on to the original post.

Lunar brace seems really good but when you start thinking about its math and circumstance, it really starts to fall off.

The math; For lunar brace it takes 50 defence to get 10 points of attack For lunar brace it takes about 34. Attacking with 30 might with lunar brace will only do 6 damage a hit.

Considering most of the units with enough defence to make a difference in attack are tanks that should be dispatched with magic, it feels like it's almost always better to go for reprisal or weapon power instead of lunar brace.

This isn't really taking into account being synced with Erika and having the benefits of solar brace but solar brace doesn't increase damage so it's a moot point when it comes to damage.

Thoughts? Disprove me? I'd love to hear it does have some viability as solar brace and being engaged with Erika is beneficial on its own.