TIL that you can't use 8 wireless Xbox 360 gamepads with the play and charge cables. You can only use 4.
Pretty sad since I bought 8 of these thinking it'd work on every game. Unfortunately, you can only use a maximum of 4 of these with the cable. I'm aware that you need 2 dongles for 8 Xbox 360 gamepads to work, but it still doesn't matter. After you plug the fifth one, it'll endlessly turn its light on and off until you plug another one off. So, for anyone wondering (having two dongles):
- You can use 8 Xbox 360 gamepads wirelessly.
- You can use 4 Xbox 360 gampads with their cables and 4 wirelessly.
- You can't use 8 Xbox 360 gamepads with their cables.
EDIT: Turns out, it can be done! Although you have to connect 4 of them to an external power source (phone charger) for them to work. Thanks for the suggestions in the comments! Also, if you were curious, you can also connect 9+ gamepads using this method. Although you need 3 dongles for this (and more if you want 4 more and so on).