Nunchucks - upgrade is FAR too strong. Maybe if it was "return the difference between the dice", which seems fair - instead of getting about 2x value from your dice, you'd get maybe a bonus 33% return on your investment? Which is a good sweet-spot for upgrades.

Master Key - more reliable but restrictive Lockpick. Seems fine!

Knitting Needle - Like an easier to play, slightly less powerful, but 3-uses version of Backstab... interesting idea! Made less useful because Nunchucks only counts every 2 dice you put into it, but there's still a lot of potential.

Wrecking Ball - a solid Crowbar sidegrade, awesome weapon, 20/10
On a more serious note, a level up reward is an interesting place to have it! Reducing your countdowns by 4 encourages you to have smaller countdowns (Plaster, Cloak, Tetraphobia), making this kind of like a "build a passive for your weapon" item. And I like it!

Befuddle - of course you'd add the single dice manipulation item that I haven't tested yet! Anyway, it seems... fine? About on par with Counterfeit in terms of usability (read: not an item I'd ever usually use, but still strong as heck), but with a bit of randomness. Ties in well with Nunchucks and Lucky 7's "return a random dice" functionality.

Chisel - Good for turning your 4s into 3s and 1s to get bonus damage from Nunchucks+.

Cloak - not a fan. Not many enemies have enough status effects that Reduce? is going to affect them that much... and those that do, this makes the fights absolutely trivial.

Plaster - a solid healing option! Stronger than Bandage most of the time (effectively MIN2 instead of ODD, and affected by Wrecking Ball), but Bandage wasn't that strong to begin with.

Dramatic Exit - OP. Overpowered as all balls. It's hard to activate, but with some Plaster/Thick Skin for sustain, you can reliably end every fight with this. Maybe it could just increase your max health by 1?

Blast Chiller - sure yeah this is fine. Nothing to comment, just a... balanced-ish weapon that's fine. Maybe a bit underpowered, but eh, that's fine!

Square Pair/Puppy Paws - Midnight Charm sidegrades, on the class that reeeally doesn't need big dice. Just like Snake Eye for Warrior, they have their uses though (SP + 2x Chisel = funchucks)

Paper Lantern - Like Lantern, this is... weird? Really situational, a bit like a delayed Duplicate. At least it's not once per battle at least.

Tetraphobia - Haven't had a chance to use this but it seems good for both paths. Upgraded, it deals 16 damage with full Knitting Needle up though...

Dramatic Entrance - unless you can instakill the enemy with Fury?, or have a once-per-battle item (you don't), then this is a bit... meh.

Raw Ambition - This is what a Curse? effect should be on. Not a "if you roll 6" effect like Flying Skull!

Signal Jammer - see Master Key

Determination - I'm not usually a fan of strong statuses being part of the "random status" pool, but for this I guess it's fine since there's a largeish cooldown?

Secret Weapon - Power Crystal on a countdown? Yeah, seems fine.

Barbed Wire - Should the description reflect the bonus damage from Thorns?? Also, how do you end a question with a PU status effect (like Burn?) at the end of it? Do you just leave both of the question marks there? Or do you put a space between them (but that looks weird)? Maybe just put 1 question mark there, but that adds some ambiguity...