You can uncheck the "Mouse Aim" setting, which is located in the Input tab of the Configuration menu. This will cause the player to attack in whichever direction they are facing.

Sorry, but the only current way to change the player's heading without a mouse is by moving. We use the Shift key to hold the player in place when attacking while mouse move is enabled, so maybe Shift should lock the player's movement when not using a mouse.

But I don't understand how the aim isn't in the desired direction. The power should target in their direct line of sight. Is there a specific power you're noticing this with?

I was talking about the "Move hero using mouse" option. Shift will restrict movement when that option is enabled, but mouse movement is the opposite of what you want. I simply mentioned it because I was proposing the idea of using the Shift key to restrict movement when *not* using mouse movement.