Yosef and the Attribute of Yesod

On the verse in which Yosef's brothers ask whether he will be king over them (Bereishis 37:8), the Ramchal teaches that the shevatim had no bad intent. Yosef's level was the attribute of Yesod, foundation, which is why he could rule as viceroy of Egypt. Yesod is inclusive, a kollel, and a king must have an all-encompassing soul. The same is true of Shaul and of Moshiach ben Yosef, who will rule in the future. The brothers' question was whether Yosef could complete the rectification of Yesod, which had been damaged by the sparks that fell from Adam HaRishon's sin and had not yet been fully repaired through the exile and redemption from Egypt. So although Yosef ruled, it was not true kingship. He was second to Pharaoh, and Yesod remained partly in the hand of the sitra achra.