I feel like when people compare Akechi to Light Yagami, they fundamentally misunderstand his character. Their similarities really end at their designs, and Light is the kind of person Akechi would despise.
Light Yagami lives a pretty privileged life at the start of Death Note. He has a stable home, with two parents and a sister who care about him. He's a successful student. There isn't really inherent tragedy to his life. The whole reason he starts using the Death Note is a mix of curiosity and a jaded worldview, and when it works it empowers him, very quickly goes to his head, as he believes he is one who can be a god of a "new world" once the shock of his initial kills wears off. While his first kill was to help someone, that altruism didn't last. He is in charge of his choices, while Ryuk mostly vibes and maybe eggs him on a little. Fundamentally, Light has something Akechi lacks: agency, and a comfortable life he took for granted.
Meanwhile, Akechi is someone who lived on the bottom rung of Japanese society. His very existence is shameful there, between his mother being a sex worker, his status as an illegitimate/"throw away" child, and his mother's suicide. Years languishing in a foster system that is notoriously inhumane, in a country where 90% of the adoptions are grown men for inheritance and patriarchal reasons, while very few children in the system find permanent homes.
When Akechi awakens his power, he approaches Shido not because he wants to kill people but for a stupid revenge plan cooked up by a traumatized child who's been nudged along by a malevolent god. He wants to build Shido up so that at the height of his power, he can expose him for the monster he really is, while another part of him genuinely wants to be useful to Shido, as Cogkechi later calls out. His feelings are a mess of contradictions, and so it's no surprise that Shido was able to mold him into his assassin at only 15 years old.
It's also worth noting that Akechi only approaches Shido with his ability to cause psychotic breakdowns. Shido is the one who teaches and instructs him to do shutdowns. He's still complicit, very sunk cost with his revenge plan, but as I spoke of here, even if he wanted to quit, he couldn't alone.
Shido's cleaner and control of the law and ability to effortlessly turn him in would render the Metaverse his only safe haven.
I think people look at 11/20 Akechi and Akechi in the early parts of the engine room and assume that's just his "true self," when in reality it's another mask. Royal makes it very clear because in Rank 7, he outright warns Joker of what's to come via a pool metaphor and offers an out (though he's MUCH happier if you don't take it/stick to your principles), and in Rank 8, he goes on that big "I hate you" speech... while Sunset Bridge is playing. Y'know, the song that plays at the end of most confidants to reaffirm bonds.
So when he smiles as he shoots what he assumes to be Joker, that doesn't mean he's genuinely happy. More likely, he's an emotional clusterfuck, given he also is disoriented enough to namedrop "Shido-san" over the phone, and in the subsequent meeting with Shido, tells him not to kill the Phantom Thieves and that Morgana is "just a cat."
Yes, he says they'll make them fear for the rest of their lives, but remember, he's talking to Shido. The things he says are likely all incredibly calculated to sound appealing to Shido. And when you consider that he planned to utterly destroy Shido's reputation after the election, the "delay" makes even more sense.
Later, Akechi goes on about how the people he induced shutdowns on were deserving of their fates, but I don't think he believes it so much as it's the only way he could convince himself that it was worth it, and given how much society failed him, and given how many of the people he targeted were likely rivals/competitors or rich fucks, I think he'd be less inclined to assume good faith.
Kunikazu Okumura was not an innocent little victim, after all. He was one of the people who requested breakdowns and shutdowns the most. I think Akechi enjoyed killing him not because of how it'd hurt Haru, but because of catharsis. Because Okumura is just as monstrous as Shido, so why should he feel remorse? However, I don't believe he feels the same about Wakaba, as when he discusses her with Shido, he mentions how her fate was because she refused to willingly work for him.
It's another justification, but I personally think Wakaba's death was the most painful for him because he was effectively making Futaba just like him. That's why I think his reaction to Sae threatening Sojiro's custody was genuine.
Anyway, evil grinning Akechi is just another mask, as I said. Keep in mind, this is someone who laments not meeting Joker years ago, someone who Morgana outright points out is lying about his hatred.
And that's the thing. Light Yagami, while a really fascinating character, is not someone who had all this childhood suffering or lack of agency. He does not regret his actions in the slightest and goes down due to his own hubris in both the anime and the manga. While you can argue that Ryuk set him up by dropping the Death Note, Light was the one who picked it up and chose to use it. Any nudging from Ryuk didn't coerce Light into doing it because Light seized the opportunity.
No, if Light Yagami is like anyone in Persona 5, it's Masayoshi Shido, not Goro Akechi. Both believe they are god/god's chosen, that they are the ones who will reshape the world to their ideals, and to be frank, both use and abuse women to serve their own purposes.
Goro Akechi goes down sacrificing himself for the Thieves and pleading with them to stop his father and again in Maruki's reality when he refuses to let Joker accept a gilded prison of a world for his sake when he knows better than anyone what it's like to have no true freedom. If you max his confidant, you see him in the postcredits, leaving his survival entirely possible, and I think it works because at the end of the day, Akechi was meant to be a victim and a foil.
Light is a villain protagonist and a cautionary tale. Though its his POV we follow, he isn't someone we're meant to root for, but I definitely don't think enjoying the character is a bad thing at all. He's really interesting! I just think that a lot of the Akechi and Light comparisons are surface level at best.
