He did give me a B knowledge from Kzarka.
Did reset it 2 time, after the second time I got again a B and then I got a A
You can reset and retry it easy with 2 chars.
Go with one char to Calpheon and reset the knowledge for 10Energy, and log in to your Char at Hakkon. And get the knowledge for 2Energy.
if it is not A+ or S, change back to the other char and remove the Knowledge again.
gives you knowledge points. (press H in game)
10000 knowledge points = 30% Global drop rate or .03% added to an items base drop rate.
the drop rate gets added after the base item drop rate for example if you invested energy in a node and got it to 10% congratulations you now have an increased drop rate on items of .01 I believe.