Manga

I really like how they made use of the eyes and contrast

Kamiki, losses his "darkness" to only be engulfed by it as he could not let go of his fleeting moment of brief happiness Ai brought, which ultimately became the "weight" that dragged him with the karma of his actions coming full circle.

Also how his life revolved around keeping things in place to chase a memory. It was a selfish gesture to make himself happy

Meanwhile, Aqua has two "white", albeit fading, lights showing how he has finally found full clarity in his actions and can actually find true peace in what he achieved, his "weight" has been lifted as he can finally feel like that pit that has made his life horrible is finally gone as he frames his life away from darkness in revenge, to finding light in living for someone else.

They are both selfish, but the difference is one took life to chase happiness and the other gave their life for someone else's happiness.

(Still feel Aqua has a good chance at living as he was floating to the surface, but who knows how it ends)

I really liked Gorou reaching up from the depths to exact his revenge on Hikaru. It actually mirrors some of the visuals from the anime's season 1 ED in which Aqua is plunged into water and is held down by red threads:

After it is all said and done though, Hikaru has not really lived up to the villainous figure that we have imagined for a large chunk of this series from Aqua's POV. I guess there is some symmetry with Ai there if you think about it.

When Aqua/Gorou got to know Ai in real life and then even more closely as he investigated her after her death, it turned out that she was just a talented person, but still a person at the end of the day. He had initially built her up inside his head as this unapproachable prodigy, but that was shattered after Akane was able to channel Ai so well in the dating show, causing Aqua's perception of Ai to start to come back down to earth. Similarly with Hikaru, he is built up as some kind of supervillain inside Aqua's head. However, the reality is that Hikaru is just a dude with an unhealthy worldview and obsession with Ai.

Edit: looking back through the chapter now, the full page spread is eerily similar to the season 1 ED. Compare the spread to the screenshot I grabbed above. It almost has to be intentional.