"tell me why he picked you"?

[Smile]

This could lead me to think that maybe someone chooses keyblade wielders. The only person who I know can even remotely be capable of this is Master Eraqus, who we dont see in KH 1 or KH 2.

No need to go that far.
Riku was chosen by Terra to wield the KK. This was more or less confirmed by Nomura when he said the Lingering Sentiment scene in the FM+, where the LS tells Sora that Sora isn't the one the LS chose for the Keyblade, implies Riku is a chosen Wielder.
LS not choosing Sora + Sora getting the Keyblade from Riku = Terra choosing Riku for the KK.

The thing is just that though about Sora - someone chose Riku for the KK, but the KK itself is what chose Sora in the end. Hence why "why were you chosen" fits a lot better than "why did HE choose you" as that's right in Riku's case, not Sora's.

 

[Axens]

No need to go that far.
Riku was chosen by Terra to wield the KK. This was more or less confirmed by Nomura when he said the Lingering Sentiment scene in the FM+, where the LS tells Sora that Sora isn't the one the LS chose for the Keyblade, implies Riku is a chosen Wielder.
LS not choosing Sora + Sora getting the Keyblade from Riku = Terra choosing Riku for the KK.

The thing is just that though about Sora - someone chose Riku for the KK, but the KK itself is what chose Sora in the end. Hence why "why were you chosen" fits a lot better than "why did HE choose you" as that's right in Riku's case, not Sora's.

Yeah this does make more sense. So then, that leads to the question of what governs Terra's right to chose who is worthy o wielding the Keyblade? Maybe the Keyblade "Masters" were to chose successors?