Ueshiba's spirituality was from Buddhism and Shinto a la omoto.
Ueshiba practiced mikkyō. This is a very special form of esoteric buddhism which has deep roots in daoist thoughts and practice.
Ōmoto kyō is a very special form of shintō which is connected to daoism via one of it's main kami, which is of daois origin.
The language Ueshiba uses, the themes he discusses in his texts and lectures are very often direct quotations of canonical daoist texts.