What it does: it increases the pal’s normal attack damage.
Which pals benefit from it: Irmgard is probably the only pal that really gets anything from this perk, because it slightly improves the Irmgard’s healing hability. I believe all other pals only get a slight normal damage boost.
Maybe Bela gets something from it too (I can’t verify for now).
The problem: Increasing the normal damage by a small margin 1) isn’t really worth it; and 2) that’s not really what a pal is about. We chose pals based on their special hability, not because of their normal damage.
This means that this cape/perk has no usefulness really, other than melting it for pearls or selling it for gold.
My suggestion: Instead of increasing a pal’s normal damage, this cape/perk should increase the pal’s special hability. For every 1000 perk points, a 10% damage increase on the special hability would actually be useful and make this cape appealing.