I always have a funeral for every youkai I killed.

At their funeral, I would offer them the flower and pray for them.

On the high heavenly plain divinely sit the god and goddess yin and yang forces in blessing, as the imperial ancestor, Izanagi Original Shinto prayers from here. Translation by Stephen K. Hayes taken from here. Full English translation of The Great Purification Norito Prayer based on the modern langauage is here.

in Tsukushi, Himuga, Tachibana, Odo and Awagi plain purified with ablution, and at that time brought into being

The divine forces of purification. That all the various defiling things, sins and impurities

be cleansed and made pure, we proclaim and request of the heavenly spirits of celestial realms, eight million divine spirits.