Fascinating history. It's strange to see what the various jujitsu-descended arts choose as their comfort level with injury. The traditional jujitsu ryu had lots of maming / killing techniques, which have been taken out and readded depending on the art: Judo focused on making a very safe art that could be applied full-intensity in a sporting context. Aikido focussed on making a purely defensive art. Then Gracie jujits…
I'm not a aikido-ist, but I've had some friends who were very high level. They explained to me the origin of aikido was as a technique that policemen could use with plausible deniability. When people watch someone fight against an aikido-ist they see: "The guy charged at him and something happened and then the guy ran right into that lamp post and knocked himself out". Whether that is really true, or I misinterpreted…
Aikido has a Paul Bunyan creator that I would say is analogous to Yoda. He was from the stories I heard, from a direct student of his Roy Suenaka of Wadokai Aikido, pretty much a modern Miyamoto Musashi and I'm sure no one will ever get completely true stories today. He started his life as a farmer, served in the Japanese Army during WW2, and had a spiritual awakening eventually leading to the creation of Aikido. He's an interesting person due to when he lived and the life he lived.
Aikido has soft (spiritual) and hard (martial) techniques. A lot of sensei's only subscribe to one or the other and there are two major societies, Ki and Aikikai. When I practiced, we subscribed to both, so we even made use of things like choke holds and punches to initiate.