The lights in the sky are the result of a battle between two or more alien civilizations. The only one that matters is the insects called "The Evil God" by their enemies, and who I'll refer to as "The Insects". The Insects are a species of insectoid organisms that seem to fully lack what we humans would consider sapience or sentience. They don't think or feel, they just have their instinctual desire to survive, reproduce and expand. Over millions and millions of years of evolution, The Insects evolved to travel in vacuum, terraform other planets and, most important to the story, turn suns into black holes to enable faster-than-light travel via wormholes, among other crazy sci-fi stuff.
The Insects arrive on Earth and land on Yonase Island in Okinawa, Japan. They begin to 'reprogram' the local insects for their own purposes, preparing Yonase Island to become their base before they go to the next star system. The local insects grow to giant sizes and terraform the island to house and foster the 'main' species, which looks like an ant with butterfly-like wings.
Their method for travel and propagation is as follows: they turn Jupiter into a series of three neutron stars or miniature black holes or something (I don't quite remember or it wasn't clear). These mini-stars have huge gravitational pulls and two of them move around the Earth and shape it into a cone, with Yonase Island at the tip. As you can imagine, devastation ensues, with mega-earthquakes and super-tsunamis. The base of the cone on the other side is made to erupt, blasting the Earth forward. The destination? Well, the last mini-star was sent into the sun in order to turn it into a black hole, which will be used as a wormhole for the Earth to go into.
So, that's how The Insects work. So what's up with the MC's alien dong? Well, in one of the previous iterations of this cycle, one of the alien species that fell to The Insects managed to capture and experiment on one of them. They then encoded into its DNA a function to seek out a non-insectoid species and fuse with it. This would in theory create a means of communicating with these unthinking aliens. Said Insect fused with the MC. The reason it became his dick is because sex is basically the exchange of information, and lots of it at that. See, The Insects, instead of using neurons and having a big ol' normal brain, use these microscopic organisms that basically have sex all the time, transmitting information between them, forming a sexy neural network. So basically sex is the most important thing to this species or something.
Anyway, how does it end? The Earth is shot into the sun/black hole and is transported to another galaxy 3 billion lightyears away. Somehow the island and a large amount of people that survived the transformation (it's not a small number, but definitely much less than half the Earth's initial population). Not sure how that's possible on a planet now shaped like a fucking cone with half of it blasted off, but why not. It's implied the MC had something to do with it, as The Insects aren't supposed to travel to other galaxies nor let the host species live so carefreely. Guess he got through to them after all. shrug