Something like text reader, inside extension context menu. It would allow users to listen to articles, blogs...
I don't know if it would be good idea to read whole page, because it would read lot of unnecessary stuff, but i think if it was just limited on selection it would be more than enough.
Translation shouldn't be only about translating to other languages, but also to other mediums like audio.
User would select text in browser, right click (or click in the popup) and select Kagi Translate from context menu (or popup menu) and then Listen to selection. Then the user could play/pause audio, change listening speed, voice and volume.