When Genji uses the deflect ability, does the deflected attack deal damage to any enemy player in its path or just to the one that fired?
The deflected attack will deal damage to everybody that it hits. You can aim the deflected attack to your cross hairs if you want to hit someone else besides the guys who are shooting you.
Attacks that are reflected by Genji are fired in the direction that Genji is facing - in other words, where his crosshairs are aiming. That means you still have to aim at your targets if you want to damage them. Simply using Reflect is not enough.