So, we know that Void Exists in All Dimensions, and take’s many different forms in each one

Void is omnipresent, and eternally reincarnating, taking new and varying forms often. 

In Hyness’ pause screen, we learn that despite succeeding in Reviving Termina, He couldn’t “Completely break the seal,” meaning that Void Termina is not at its absolute 

But when we fight Void, who has seemingly come to be naturally, it looks like this, and is much more powerful.

Like Zero, and its backdrop is absolutely a reference to Hyper Zone. 

From this, we can deduce that Zero is a naturally occurring, near perfect form of Void.  
This means that Dark Matter are simply reincarnations of Void. 
THIS explains why Zero and Zero Two are different entities. They are two distinct reincarnations of Void.

And since we know that Void takes alternate forms and exists in ALL dimensions, then We can deduce that entities like Dark Mind are ALSO Void. 

Now, this is getting into more personal speculation, but the question one could ask is HOW Void forms. 

My personal idea is that Void exists everywhere, but can only take a physical form when given a Catalyst.
Before this, we were under the impression that Zero and the Dark Matter were the physical culmination of all the Negative feelings in the universe. 

These negative feelings were the catalyst from which Void used to take form. 
VOID uses mirror attacks in its fight. Void could have used Mirrors as the catalyst to take the form of Dark Mind.

If you bear with me for a second, Nightmare was sealed in the fountain of dreams. If we consider Nightmare to be void, could we assume that Nightmares were the catalyst which Void used to create him?

With Termina, the Jamba Hearts and the gathering of negative energy was the catalyst from which he was formed. (or, a soul?)
And so on. 

And thus, when you consider the idea that Void simply needs a catalyst from which to take form, then it makes perfect sense that positive forms of void could be created. All that would be needed would be the gathering of positive energy instead of negative energy, which is something star allies itself acknowledges. 

So, If Kirby is Void, which is implied by the game, what was the catalyst for his creation?
It’s a bit of a stretch, but Kirby has, since the beginning, been referred to as Kirby of the stars. 
Stars have distinct power in the Kirby series. The Star Rod, the Warp Star, and so on. Could Kirby have been formed using the power of stars?
It’s a bit of a reach, but a conclusion none the less.

Now, here’s where we get to a personal idea.

Since we know that Void Termina is a incomplete version of Void, then we can assume that Void is the perfect form of it.
Does this mean that Perfect and Imperfect forms of void exist?
Personally, I believe this to be so, as we have at least four examples OF Perfect Void.
Zero

Zero Two

Void

And Magolor, under the control of the Master Crown, which, thanks to Termina’s boss fight, we can conclude absolutely uses Void as the source of its power.

Notice the similarities between all of them. Yes they all take different forms and have separate characteristics, but they share their eye and body colors in common. This means that these characteristics are one form that perfectly matured void can take.
All of these are examples of Perfect Void
And as such, Imperfect Void must ALSO exist. Void that has not reached this absolute.
There’s still a lot of leeway for what counts as perfect or imperfect void, as, like stated before, Void takes a MYRIAD of forms depending on the catalyst and the dimension its in. 
But here’s my list, I guess

There’s lots of different criteria that could be used that could change this list. If u want to see the alternate ones just lemme know.

You might be wondering why I listed Soul Forms in the Imperfect Void section, so here’s why.
VOID shares attacks with many of the soul forms throughout the series, as do the soul forms with each other. 
So, what if, Soul Forms are simply a host gathering Void in some way through their desperation?
What if the intense grief of the host being defeated/dying are the catalyst through which void is gathered, and their body becomes the host?
But the reason most soul forms are noncanon is because most people cannot cannonically absorb void.
Just speculation, but that WOULD place them within the Imperfect Void section.

This is already too long but like.
Here’s most of my thoughts on Void.
I have more, send an ask if you want more of my VoidCanons (void headcanons)