Turaga Vakama is there to explain how Krakua appeared to use his Kanohi power through the Kratana. The theory below is used to explain the inconsistencies between my claim that Kratana cannot transmit Kanohi powers, and the scene that appears to show Kratana transmitting Kanohi powers.
During the vision, Vakama is wondering how Krakua seems to be reading his mind, at which point Krakua tells him about his Kanohi power. Krakua gave this answer because he knew what Vakama was thinking.
If he wasnât using his Kanohi, the only way for Krakua to know what Vakama was thinking at that moment is to ask Vakama himself. So, at some point before Krakua sends the message, Turaga Vakama tells Krakua â15 seconds into the vision, I wondered how you read my mind, so you should say that you have a Suletuâ.
So Krakua wasnât actually using his Kanohi power on Toa Vakama, he just had prior knowledge of what he was going to say, since he already said it to Vakama, and Vakama can tell Krakua what he said/will say.
This explains how Krakua knew to tell Toa Vakama that he has a Suletu, and I just took it one step farther to say that Vakama gives Krakua the entire speech.
Although that does mean that no one actually wrote the speech.