So for the people here who say that Aiki is the opp of Kiai or there is no Kiai in Aikido, can someone then explain why O'sensei always used Kiai. There is plenty evidence in the videos with sound you can here his Kiai, the old people in the Iwama village talk about hearing Osensei screams coming from the forest and dojo day and night. Saito Sensie has explained indepth about its connection to Aiki. So can someone explain where and why it was changed?
I've never heard that aiki and kiai are opposites. I think where there is no kiai used, it's generally from the idea either that it's superfluous or that it is
being used, but silently. O Sensei didn't make loud screams after every technique, so it follows that it's not always needed, or not always expressed loudly.