Personally I think the second phase is much too easy, it's just parry, riposte, parry, riposte. Rinse repeat victory.

While the first phase is more challenging, it's a multi boss, it makes you paranoid. When's the helper gonna rise? Where's he gonna rise from? Keeps you on edge, but the third watcher that "helps" you if you don't aggro him first, can easily provide a healing window, keeping it fair.

I don't really care.
I like the fight. And the poses.
That's all that matters to me.

Oh yea, the fights are exhilarating and amazing, one fuck up and you have to start all over.

This was more meant to be a picture of a character in a pose of a character I particularly like.
Not an analysis on the boss fight. But since it's turned into that, I'll explain it from my eyes.
I had never played Dark Souls. Ever. It took my friend gifting it to me for me to like it.
I was nervous and had never played them, ever. It took me six tries to beat Grundyr.
I watched a boss tutorial and learned when to attack him. So, I practised rolling and when to be aggressive.
As it went on I summoned my friend and for the most part he fought the bosses for me.
Yes I did stuff but he knew much much more.
The first time I EVER faced a boss alone was the Abyss Watchers.
He told me to wait, but I got bored as I wanted to play.
I can tell you. I never saw any of the bosses beforehand besides Grundyr and Vordt.
Everything after that was a mystery. I went in assuming it was a Boss Fight.
And my first attempt, I died. I knew nothing of parrying or anything in the technical area.
Just rolling and attacking. And occasionally blocking.
So to me the fight was much more challenging. I had no clue that the third Abyss Watcher helped you either.
So on my second attempt I still attacked the third one.
I defeated its first stage and assumed I had won. I was ecstatic. But oh no I was wrong.
It got back up, moving faster AND burning me if I got too close and wasn't careful.
So I had to think on my feet.
So I did. And because of that I won.
The boss fight, when I've asked anyone who played it for the first time or a veteran have usually said the same thing.
It's the introduction to a dark souls boss fight.
For beginners it's a challenge of wits and timing. Grundyr was just rolling and attacking after he leaps then rolling into him in his second stage.
And Vordt is just roll behind his ass and attack. The Abyss Watchers played more aggressively and had a much scarier feel to them.
On my solo playthrough I can tell you for certain that while it isn't my favourite boss fight, that being left for the nameless king, it's definitely in my top three.
It made me feel like I had DONE something. It made me feel like I had won against a struggle.
Grundyr and Vordt felt good, but nothing like the Abyss Watchers made me feel after defeating for them.
And then I used the soul for more souls since I was an idiot and my friend didn't tell me to preserve the souls.

The first time is always the hardest no doubt, I had trouble too on my first time, the first time is death death death death death, even though I had experience with dark souls games beforehand with 1-2 and Bloodborne, it still easily kicked my ass to the moon and back, I have used videos and tutorials in numerous fashions too, by now I'm on New Game plus 24, with almost 600 hours of playtime, so I've had time to go from the ground up, to watch every single pattern and attacks, learn the hard way what can and can't be parried, even longer to get the timing right, but I too started from the bottom. Heck I didn't know about the dark lord ending till New Game plus 5.

Ooooo looks so cool, really love the design overall n_n