mybe they all are not good maybe some keyblade welders are evil

yeah, like Riku at Hollow Bastion in KH1. he had a keyblade, and he was evil for a little while.

yeah but maybe that wasent him he was controld by that dragon lady

yeah, but he had a keyblade. and since Maleficent was controlling him, he was evil for a little while, I guess.......

So far the keyblades seem to be pretty good judges of character, though I wonder if they would abandon their wielder if they started to use them for evil. I also wonder if it would be possible for a keyblade itself to become tainted.

ummm your right how about rikus evil keyblade also bhk
is good right

Now that, is a good question. Thus far all the videos have made him seem to be a hero, though with Sora's new darker costume, perhaps it will become a sort of Tsuzuki and Muraki contrast situation (Tsuzuki is a good angel of death who wears all black, and Muraki is angelic, wears all white, and is one of the nastiest anime villains ever ^_^).

this is a little off topic, but I just noticed something. Tsuzuki is good, and wears all black, and Muraki is evil and wears all white. the BHK wears a perfectly balanced combination of black and white. so that must mean that he is good AND evil.

Actually Rikku was pure of heart when he used it. He beleived that he was using it to save Kairi, and so his heart was pure...The keyblade saw him in the same way as Sora, and when Sora found that he had a reason to weild it more than Rikku, the keyblade was returned to his keeping. So it wasn't that he was bad, his state of mind was right...

i think you're on to something.

Riku was doing only what he saw necissary to save Kairi. It was Malificent who confused him into doing evil deeds. He only did what was seen to be needed to save Kairi.