Sidescroller Shooting?

3D sidescroller shooting in angles WITHOUT a mouse.

Hi guys, I’ve been searching on the web for the answer for months but I haven’t been successful.
The question is simple, but the answer seems to be something sacred and very difficult to find.

OK, let’s go …

How can I create a script of mechanics similar to Bass or Axel (from Megaman) from sidescroller 3d shooting game? How to make a 3D sidecroller character shoot at angles or aim WITHOUT a mouse.

All the answers I found on the internet is about to aim using mouse location, but in my project the player will not use the mouse. Only the keyboard or gamepad.

I want to make my character shoot or aim at + and - 45 degrees to the left, right, up and down using only the gamepad’s directional movement control with a aim button (like LT + directional button to aim and X to shoot)

The question seems to be simple, but the answer just doesn’t exist!

I need your help and thanks so much for the time wasted to give a little attention to my task!