#normal guy posting

Oh, Shalem's is the funniest by far because he's out here wielding a shield based on a Gorgoneion of all things.

Gorgoneion were basically depictions of the Gorgon's head on amulets, talismans, shields, and other such utensils, believed to be a magical protective symbol; Athena and Zeus both wore Gorgoneion pendants, for instance.

It's incredibly fitting for Shalem, since it looks incredibly sinister and intimidating, but it is fact a good luck charm, and likely an attempt to shield himself from his backstory.

Granted, his lore states that he's also skilled with daggers; his desertion began when he used his blade to cut the ropes that bound his would-be victim and then giving them the dagger so they could fend for themselves after he let them go.

So, tying this back to your ask:

Jaye's knife is just a regular, high quality kitchen knife. Sharp, but mundane, an excellent metaphor to how others see him versus how he sees himself.

Mr. Nothing's fan is a tragic keepsake as much as it is his weapon. As much as he wants to run away from his past, he carries part of it with him at all times nonetheless, as his beloved master entrusted it to him before her death. This is also an excellent time to remind you that, even though Mr. Nothing is a funny lad who wouldn't hurt a fly if he could help it, he did say that his ultimate objective is to return to his hometown one day and "settle his debts".

Shining's staff is very much her sheathed blade, presumably her weapon of choice from back when she was in the Confessarius. Appropriately enough, it is a past that she'll eventually have to harness again in full, and the blade shall part from the sheath for good when this happens. It is also likely highly conductive as an Arts medium if she can use it as a staff, much like Nearl's mace is simultaneously a blunt weapon and an Arts catalyst.