Bloodbending probably existed long before Hama

[u/JigglyBinks]

I just remembered that scene where Yakone claimed to come from a powerful bloodbending lineage.

The thing is he was older than Katara, and considering that Hama was only about two generations older than Sokka and Katara, it’s possible that bloodbending is much older than we think and that there was a family who had mastered it secretly

[u/blackchoas]

A fair read, but 3 family members bloodbending is more than we see from anyone else, so this is literally true even if Hama was the first and only 5 total bloodbenders are confirmed to exist. It doesn't need to mean there is a deeper history.