I tested battles with each number of scrolls, and from what I can understand, they are:
| Equipped | Granted Perk |
| 1 scroll | Reveals opponent's weakness in Badass mode, if you already knew it in Normal. |
| 2 scrolls | Reveals opponent's weakness in Badass mode, without needing to know prior. |
| 3 scrolls | Reveals cursed opponent's weakness in Badass mode. |
Also, if you equip 2 or 3 scrolls, your battle-moves get color-coded to show their effectiveness:
| Color | Meaning |
| Grey | Opponent hates it. |
| Green | Opponent likes it a little. |
| Yellow | Opponent likes it a lot. |
| Red | Opponent's weakness. (Red is only shown with 3 scrolls equipped, otherwise it's colored Yellow.) |
Here's an example with 3 scrolls equipped:
