 Complete the following phrase:  In 1858, he was restored to the post of rōjū by the Tairō Ii Naosuke, and quickly was seen as Iis right-hand man, taking a leading role in difficult situations, such as the Ansei Purge, the ratification of the Ansei Treaties, and the opposition to Hitotsubashi Yoshinobu from becoming shōgun. In particular, his heavy-handed approach to forcing Emperor Kōmei to accept the ratification of the 