Lore - Phase 4

This is the phase of taking over the planet Earth and eating all - or most - humans.

The phase of consumption.

At around the year 2034, the few perennials that were still in their home dimension, and the ones who are already in ours, can't wait any longer. The last few also enter our dimension and the takeover begins. This takeover is a war. After they have infiltrated most of human society and our governments, and gained a following, they strike.

During the first stage of Phase 4, the initial strike knows as the the Wild Hunt, the tank heads start a bloody revolt. Their goal is to take over the planet and enslave humans. This means that they can become the new ruling species and turn the humans into their livestock. They are to be eaten to ensure the immortality of the perennials. The humans naturally don't want that to happen and fight back fiercely. Even some tank heads join the resistance forces and turn on their kin.

Why humans specifically?

At the time of the takeover, it is mostly a theory that consuming humans that are either alive or only recently deceased will work for extending a perennial's lifespan. It is assumed that it works because the human bodies are so similar to the tankhead bodies. There has been no way for them to scientifically prove it yet, but some of the perennials who have been in our dimension for a while already and tried eating humans "before it was cool" claim that they felt a difference.

Unsustainable Struggle With Hunger

Back in their home dimension, the perennials were star-like creatures. To survive, they had to feed. A perennial who doesn't feed dies and turns into the equivalent of a black hole. In their star-form, this is achieved by consuming other perennials. For a long time, they didn't think anything of it, but eventually, the smartest ones realized that this lifestyle wasn't sustainable.

In this ecosystem, everyone was a predator. No one was safe from being eaten. In fact, they consumed each other faster than they could produce new offspring. They decided that they had to find another way of surviving.

Scouting out other dimensions, they soon found ours and found it suitable for their purposes - consuming the life there.

Merely A Flesh Vessel

A perennial who enters our dimension can be killed by disease or injury, but this only destroys their temporary meat body. Their true "essence" returns to their home dimension when this happens, from where they can simply return with a new body.

Of course this process takes some effort and energy, so unless they make sure to feed upon returning again, they may become too weak from multiple entries to attempt another one.

And then... what?

Eventually, their new food source will probably be depleted, unless the perennials manage to keep a stable human population alive through whatever means. They are of course concerned about this future at the time, and different "camps" have formed. Some want to start a breeding program of sorts, others insist that they can just find a new dimension and eat all life there once their food runs out in this one.