I take back what I said before. The first time fighting him is incredible, but since then I have faced and beaten him 2 more times (game completion and Hero Mode) and I found it rather boring. The pattern to hit him is way too simplistic and the lightening round can be forgotten so easily. I didn't shoot one lightening bolt at him in Hero mode and beat him in under 2 minutes. All the battle is is SPOILER: three sword hits, shield bash, repeat. Lightening round is shield bash, three sword hits, shield bash, repeat (depending on if he gets the bolt or not).
The first time through, I was in awe. Now, it's way too easy and it feels like I've been ripped off from an epic ending to an epic game.
I know that the more you beat the bosses, the less cool they seem, but I was hoping for something more like Oot or TP that had the epic feeling and the longness a final boss deserved. Ganon in Oot always gets me shaking with nerves while Ganondorf/Ganon in TP always keeps me on my toes. I felt like this battle missed so much of its potential in both aspects. I have more trouble beating Koloktos than Demise and more nerves when facing Tentalus (beat them all the time in boss rush mode) and I just think that is wrong.
Still love the game, but wishing it would have had a better final battle.