Why did Emperor Uda rule for a time without a Fujiwara regent or kampaku?

Emperor Uda was able to rule for a time without a Fujiwara regent or kampaku primarily due to the death of Fujiwara Mototsune in 891.1

Following Mototsune’s death, Emperor Uda chose to keep the powerful kampaku position vacant. Instead of relying on the Fujiwara clan, which had dominated the court through intermarriage with the imperial line, Uda sought to diminish their influence by selecting his advisers from members of minor noble families.12

A key part of this strategy involved promoting the renowned scholar Sugawara Michizane to high-ranking positions to serve as a political counterbalance to the Fujiwara house. This period of independent rule was notable because Uda was one of the few emperors of that era whose mother was not a member of the Fujiwara family, providing him with greater autonomy to challenge the clan's traditional grip on government authority.13