He looks familiar. I think he's Seraphim, from way back in Part 1 right?! Err maybe Seraphim was a Locust devil fiend? Either way... that lines up with both being related to judgement
That's right! He is Seraphim in the first part. Seraphim in the Bible is considered the highest of all angels guarding God's throne. I have a personal theory that Chainsaw Devil is related to God in someway. Humanity before the Chainsaw Devil erased some concept was vastly different. Makima mentioned in Part 1 that humans used to have a sixth sense erased, meaning humans used to have "magic/psychic abilities" but was erased by Pochita even the 4 ways Humanity can become after their life ended(Chater 84). The chainsaw originally have a lot of power but after consuming so many concept people only remember the chainsaw's ability to chop down tree (Chapter 170). I find it so interesting that the Locust Devil appear now of all times.
If Chainsaw was related to anything Biblical, it'd be maybe Lucifer instead of God. The way he fell from grace becoming Pochita lines up more with a fallen angel than God. BUT maybe he is a god because he was once feared by many a devil and now faith in him has dropped, similar to real world belief in God. But his praise by the Chainsaw Man Church could be likened to the satanist movement, so he's Satan. But historically people's faith in God suddenly flared up when they thought the world was gonna end and doomsday cults took advantage of this, so it could be that- it could go either way! That's what makes it so exciting!! (╯°Д °)╯╧╧ We don't know what will happen next, but it's exciting!!!
That's why Fujimoto is the GOAT. I personally think he is more related to God rather than Satan, he is called the 'Hero of Hell' for a reason, he is one of the few devils that is friendly to humans, he also have heavy implications to God through his followers mentioned in Part 1 such as Principe (Principality, a type of angel responsible for divine will enactment on Earth), Seraphim (Mentioned above), Dominion (an angel responsible for Divine justice), Virtue (an Angel responsible for the enactment of God's miracles), Power (an angel responsible for cosmic order), Angel (Self-explanatory), Beam(This could be a reach as it might reference Cherubim, an type of angel responsible for endless worship and praise to God like our Beam endless praise for the Chainsaw Devil). All of them points toward Chainsaw Devil being related or maybe even be God himself. That's what make Fujimoto such a good writer, he may have already thought of many things already even planned ahead further than we may expect.
This is my favourite devil design by far. The implications is so cool as locusts are a blight to the world, it is a reference to the Bible symbolizing both divine judgement and famine.