I've played through the DG main quest a couple of times, but always felt as if I needed to use Auriel's Bow exclusively during the fight. Some users here have commented on using other weapons or tactics to defeat him, including werewolf form.

My question is: can I just attack him any way I like and use Auriel's Bow only when I need to shoot him when he is recuperating, or do I even need to use it at all? If I had my old saves, I'd just reload one and experiment, but no such luck.

You really don't need it to kill him. But it helps.

I've defeated him by using Auriel's Bow exclusively during the fight, and by using shouts and spells for the bulk of it and only using the bow to knock his shield down while he's regenerating health.