sudomod

is there a way to solder the teensy to the pi without the need of using a usb to power it and connect it to the pi?

The teensy is used to make a USB device (keyoard or controller). If you want to wire it without the usb, you could solder to the USB in the Pi or to a USB hub, or you could leave the teensy away and use the GPIO as it's mentioned in other threads.