My heart is still racing. The battle against the final two Masters was about as intense as I expected, but delivered in a much different way.
First Aeron gets a free attack on each of them. These attacks pull them out of the wall they were attached to and leads to its crumbling. Bringing down this wall opens the room up to the size of the game's usual boss chambers and also joins the Dawn Tower to the Dusk Tower (or vice-versa). But then the real fight begins.
Each Master has its own attack (a light beam for the one of Dawn and a homing shadow ball for the one of Dusk) along with a secondary attack that leaves a sword-like thing sticking out of the ground.
So long as Aeron steps out of that secondary attack's way.
Dodging isn't particularly difficult, though at times one or the other of the Masters will trap Aeron in the luminescent moss that's all over the interior of these two Towers.
To get them to expose their succulent Master Flesh Aeron needs to grab one of the swords with the chain and then throw it at the opposite Master. Light swords go to the Dusk Tower's Master and shadow swords go to the Dawn Tower's Master. It's pretty simple.
Now, I had been forewarned in the guide I was following to get through these last two Towers that these Masters need to be finished off at relatively the same time. Otherwise the one that Aeron vanquishes first might revive while he deals with the other. So I winnowed each one's health down fairly consistently. But I was not expecting the little cutscene that followed the fight in which Aeron goes for the Master Flesh but both Masters also chase down their essential bits.
Luckily, after having wielded it for so long, Aeron's proficient enough with the chain to snag both chunks of Flesh and pin them to a pillar, well out of reach.
It's a very engrossing boss fight. And all the more so when your sensor bar is at just the right distance to pick up your Wiimote's signal. Whenever one of the Master's Flesh was exposed but the pointer for the chain disappeared I waggled all the harder until it came back on the screen.
Also from that guide that I had used I learned that if you're bound for the worst ending, the final boss is fought on the lawn of The Observatory.
Having stepped outside after Elena ate the Flesh, had her vision (which I think confirmed that the couple that's starred in them all were the last two Masters or are the game's final boss), and then rested up, I can say with confidence that I did not get the worst ending.
Since I cultivated a decent relationship with Elena, I'll probably get the game's standard ending. But I'm not expecting the "best" one, whatever that might entail. Though I won't know for sure until my next session.