My mind don't really register the pet name Aki-kun well; Sekai used it as short for Akira, but separately Aki itself in kanji can be (an almost unambiguous one as well) written as 秋, which means Fall/Autumn, a season apparently Kumon-mi is about to have due to the rising of the third god.
What if the third god is some kind of separated, sealed off mentality of Akira after the accident that represents the Aki-kun back then? The third god has always been lacking descriptions in physical forms compared to the first two, and has been more portrayed as an incarnation of mental ideas: voice inside your head, embodiment of perception (Paredolia), etc. So the question becomes if it's at all possible that this voice, perception, personality, or whatever you want to call it, originates from a very OG version of Akira whose mind hasn't been traumatized, broken, and wiped clean to a point that the original can be viewed as a different individual compared to all the other Sensei iterations.
Again this is a
"_____?! Half-Life 3 confirmed!" level of speculation stemmed solely from my inner dweeb getting triggered by his pet name, as there are more pieces of the puzzle left unused (the one that boggles me the most is what another name the third god knows Yumi for is, and how), but I guess why not make the Aki-kun the third god when the other two individuals on the car have twistedly become the first two gods that day.
(this is on the assumed basis of orb of light = horny ball of light = his brother Nozomu, and tree with roots of wire = smashed Sekai; though the Sekai part remained to be verified)
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