I know that the most likely reason this happens is that the creator's simply couldn't think of one at the time but as for a story-wise explanation I have an idea of why some Keyblades we've seen lack Keychains.

Ends of the earth, Stormfell and all the Keyblades in the Keyblade graveyard have something in common. None of them have Keychainsthe first time we see Ends of the Earth and Stormfell in KHIIFM, they don't have Keychains. At this time both of their wielders are trapped in darkness, Aqua is wandering the Realm of Darkness, and Terra is imprisoned within his own heart by Xehanort's darkness. It could be that when a Keyblade wielder is lost in darkness (as opposed to being broken-hearted like Ven) that their Keyblades Keychain vanishes, symbolizing the connection of weapon and bearer being severed. This means that the lost souls from the Keyblade War could be wondering in darkness somewhere.

 

This is likely another one of those questions that is considered to unimportant to be canonically answered, but I think my reasoning is sound.

Edited December 4, 201311 yr by Isamu_Kuno

This sounds about right.

I have a simply answer:

^ Namura 

Well, that is a very interesting theory, but as stated in the gif above, I don't think Nomura even paid attention to that. It would be pretty awesome though.

Wow, that's quite an excellent theory. To be honest, I've always pictured the keyblades looking very plain-like a stick-withouth their keychains. Nothing very symbolic here.

Wow, that's quite an excellent theory. To be honest, I've always pictured the keyblades looking very plain-like a stick-withouth their keychains. Nothing very symbolic here.

I kind of more so imagined them (basing it partially off the KH II secret ending) taking their true forms without their keychains.

 

Though what if a keychain is symbolic of the chains of friendship in one's heart. And if one's heart is lost to the darkness, there is a chance only darkness in one's heart. This would explain why when Riku took the keyblade in KH it took its original form. Since Riku didn't have the connections Sora had.But why would have keyblade have no keychain at all? I would have to guess the default keychain for a keyblade is actually marking the user's connection to the keyblade's heart. As we learned all sentient things can have hearts, and keyblades CHOOSE their masters. (most of the time) So, if a keyblade doesn't have a keychain that would mean its master has no connection to its heart, or that the keyblade has lost its heart or never had one to begin with. Let's look at the heart unlocker (made from the hearts of 6 princesses of heart), I guess this arguably had a heart, but did it ever bond with or choose its master creating a chain connecting their hearts? Probably not.As for the keyblade graveyard, what if it isn't actually marking the death of keyblade wielders, but keyblades that lost their hearts. (or I guess like you said the bond between them and their master was severed, thus causing them to have nothing to manifest as a keychain)Ends of the Earth in KHII FM still considered the Terra's its master, but it lost connection to his heart, so it doesn't have a keychain.Stormfall in KHII FM had a similar situation as Ends of the Earth, it lost its connection to its master's heart. (why else wouldn't it be helping her in the ROD)Well, that's my counter theory.

Edit: I just realized that Stormfall and Ends of the Earth aren't the default forms of those keyblades, so I don't know if my theory holds water in that aspect because I assumed they would return to their default forms. Though maybe if their connection with their master is severed they are locked in what ever form they are until they can use a new connection. (since I assumed their default keychain represented a connection to the keyblade's heart)

 

 

Edited December 4, 201311 yr by Tigerruss

Game developers sometimes forget some digital art parts or whatever. Pfft. Its one out of the millions of video game glitches. (Apologizes for bad choices of words )

I know that the most likely reason this happens is that the creator's simply couldn't think of one at the time but as for a story-wise explanation I have an idea of why some Keyblades we've seen lack Keychains.

Ends of the earth, Stormfell and all the Keyblades in the Keyblade graveyard have something in common. None of them have Keychainsthe first time we see Ends of the Earth and Stormfell in KHIIFM, they don't have Keychains. At this time both of their wielders are trapped in darkness, Aqua is wandering the Realm of Darkness, and Terra is imprisoned within his own heart by Xehanort's darkness. It could be that when a Keyblade wielder is lost in darkness (as opposed to being broken-hearted like Ven) that their Keyblades Keychain vanishes, symbolizing the connection of weapon and bearer being severed. 

Another branch of this theory is why do keychains look the way they do. Take the Kingdom Key for example, when Sora had recieved said key it had a chain, symbol of King Mickey. Why? And I always found it curious/ a loop hole in KH1 story line as to how King Mickey knew there was someone with a 'key'.

 

This is all beside the points as you and others stated, maybe laziness plus how in KH1 (being the only game out yet) there were only three known key blades (Kingdom Key, Keyblade that unlocked people's hearts and the King's Key) and keys were rare in that game.