Forged Destiny [Book 7: Ch. 5]

Piercing Thrust, a stabbing blow that penetrated through magical shields and defences but was otherwise just a stab. We'd only discovered that one because no one could understand why a `Skill` would essentially be no better than a normal thrust. It was Crocea Mors going through and completely bypassing the magic on an enchanted helm that proved it.

[...]

I'd also come to realise that I couldn't rely on the actual `descriptions` of them that I instinctively had in my head.

After all, "a mighty thrust that pierces a foe's defences" hardly equated to, "a typical thrust which ignores magical spells or defensive augmentations but has no effect on armour".

—Forged Destiny [Book 7: Ch. 5]