NintendoExtensionCtrl VS ESP8266-I2C-Driver

There are lots of libraries to talk to Nunchuks. I recommend this one.

Classic controller != wiimote, it's an expansion that plugs into a wiimote over I2C, so easy to attach to a microcontroller, there are several Arduino compatible libraries people have written for it like this, https://github.com/dmadison/NintendoExtensionCtrl , then for turning that + a couple of GPIOs into a USB controller can use an arduino HID joystick library on any of the 32U4 based arduino boards https://github.com/MHeironimus/ArduinoJoystickLibrary

Can someone point me in the right direction? I know nothing. I've been looking at how the code is formed here: https://github.com/dmadison/NintendoExtensionCtrl and have uploaded the example to my arduino to debug it through the serial monitor. Other than that, don't really understand. I did manage to make it spam keyboard letters on accident.. I would love to know how to use this as a game controller on my pc using keyboard keys.

(For what it's worth, you could also try a pre-existing library with Nunchuk support).

I haven't seen anyone use that particular library with the ESP8266 yet. I've personally tried the core Wire library, the Enjoyneering library, and the brzo_i2c library. The only issue I see offhand with that Multi_Bitbang library is at line 185 in the source: it's only waiting a half bit-time for the ACK, which will fail (NACK) with any part that does clock stretching; it won't see the ACK. The I2C spec allows for slave clock stretching on any of the bits, although I've only seen stretches on the ACK bit myself with the parts I've used.