Pikachu has great protest tradition as well:

https://en.wikipedia.org/wiki/Tía_Pikachu

Sure, HA talks to its voice integrations using the Wyoming Protocol, see here for a list of available services: https://github.com/rhasspy/wyoming

You can, for example, follow the link to piper, run the docker container on your home server and then add a new “Wyoming Protocol” device in HA (you will be asked for IP/Port). You can then select your new STT service in the settings for Voice Assistant.