It is a kind of greeting that the one and only ksi uses within his group of his friends. Akneehow is a better way of saying hello
Bob: Yo my dude
Josh: AKNEEHOW!
Bob:Is there something up my dude
He a nice person and will give you what ever you need. But he probably sells drugs
Person 1: Have you met Pablo
Person 2: Yeah he is so nice and his drugs are amazing