[The sapient dagger] was a 1d6 but let you attack again, but rolling a 5 or less on the die makes you insane because the dagger insults the user so badly for missing. [… T]here was no cap on how often you could attack again.

You’re right about the extra attack, of course; I was too tired to remember or to go back and read again before commenting. I think we’d need a few things clarified before properly balancing an alternate version:

1. Rolling a 5 or lower on the extra attack’s attack roll, or its damage roll? Presumably either way it refers to a raw die value.

2. “No cap on how often you could attack again” - no cap on uses per day, or could you just make additional attacks within one round until you decided to stop (or died)?

3. Does using the dagger’s additional attack take your bonus action, or is it a free action? This may be answered by #2, since if it’s unlimited per round it must be a free action.

3a) If it’s essentially a free action, does it get included with a class’s Extra Attack? Which is to say, does it count within the activation of that ability for the purpose of anything that might positively (or negatively) impact all the attacks within a given activation of Extra Attack? (Of course, it wouldn’t make sense for it to have to count AS one of the class’s Extra Attacks, since it would be categorically worse as it would just invoke the risk with no compensating benefit.)

it immediately gets tangled up and take 1d6 minutes per 5ft of rope to untangle

Should be a Dexterity check per 5ft per 1d6 minutes to make it even more diabolical.

I played a campaign where we had a dagger of healing. It worked great against undead (as intended by the DM) and also to torture information out of people (not intended by DM).

I like letting my players figure it out. If I don’t pack the game with contrived stats they’ll spend all night investigating an unlocked door.

Wand of magic missile.

Occasionally shoots cum.

That makes it too easy: just attach a ropeladder to the broom. That doesn’t work if the broom stops levitating when you get off.

Amulet of speak with the dead - cursed. Once attuned the user can speak with the dead, but can only interpret chat with the living as wailing, any attempts to speak with the living will sound like wailing to the other entity. Removing the item does not break the curse.

OK so what’s the downside?

This sword is enchanted with fire magic!

…The handle is made of super flammable material, though, and a bunch of people got third degree burns trying to weild it. There was a massive recall.

You know what “recall” means, though? Collector’s item! These are rare af.

Praytell the price on yon banana blade to your left, fair merchant? I find it somewhat a-peeling

Ask the beholder you were trying to hit with a magic missile.

A magical sword that extends, but the longer you have it, the longer the incantation you have to say to get it to extend… Maybe show it some pictures of people cleaved in two, or try stabbing somewhere else to get it going.

Scroll of Gorilla Warfare. When used summons 15 gorillas. These gorillas are wild and do not obey orders given by the caster.

If my PCs responded to the clowns this way, I would absolutely make the clowns demons and the “bag of holding” a portal to a circus themed layer of the Abyss. And that’s the campaign now.

It turns out the ruler of this layer of the abyss appreciates your lust for violence and mass murder. That’s probably not actually… good? For you?

I don’t know about you, but the prospect of becoming a warlock themed around blood, flesh and clownery sounds pretty sweet to me!

I’d definitely play that campaign.

Dagger of purification

Can only be used to heal wounds inflicted more than 1 hour ago. Each recent use on the target reduces the effectiveness of the dagger’s healing powers.

Folded in a random axis.

V3, your eyeballs are only visible when your eyes are open.

That indeed would make it significantly less useful.

I would definitely let you play that in my campaign. Also reminds me of that bad guy from One Piece.