I had an idea for three different trinkets that knights could use. They would be:

Hilt Wrap (for sword users, looks like a red Miracloth)
Infrared Lens (for gun users, looks like a red Gel Core)
Short Fuse (for bomb users, looks like a red Gremlin Gizmo)

Each of these wouldn't have a direct effect on the weapon's damage. What they WOULD do would increase that weapon's special effects. For example, a knight using a Haze Bomb has a good chance of causing minor stun. With a Short Fuse, however, that changes to having a good chance of moderate stun. Or, possibly, a great chance of minor stun.

Since these are trinkets, which require a special energy purchase to use, these could be interesting items to add to circulation that wouldn't tip the scales too in favor of the user. At the very least, they'd be easy to create visually.