First off, let's start off with what we know, for sure, about the feat
- Golden Weapons and Mega Weapon come into contact with each other
- Weapons shoot into space and through, something, a star is created
We know, 100%, that these things happen, but now we need to know the method by which it happened. Let’s now lay out the point i'm trying to make
- Mega Weapon and Golden Weapons come into contact with each other (Here and Here)
- Mega Weapon and Golden Weapons fuse or combine in some way (Here, Here, Here and Here)
- The Weapons (Golden and Mega) shoot off into space (Here, Here, Here and Here)
So with these, we end up with this chain of events
- Ninja use the Golden Weapons against the Mega Weapon
- Their powers combine and float towards each other, circling around the Mega Weapon and fusing with it
- The energy resulting from the fusion shoots all the Weapons into space, where they explode
- Upon that explosion, a star is created
- The weapons land on a comet afterwards
Now with it all laid out, it looks rather consistent with what the series and external sources show. The Weapons exploding in space makes sense, since in every showing of them coming into contact with each other, they explode. Now we have other points to address, such as the Time Paradox. This can be solved easily by destroying the Mega Weapon, but also destroying the Golden Weapons too, removing both the Mega Weapon and the Weapons used to create it, therefore preventing both the Ninja and Garmadon from having the weapons, thus fixing it. Now we have
Tommy’s statement of the Mega Weapon becoming a star, with this, we can say the Mega Weapon was destroyed upon going into space, but his statements on the Mega Weapon have been inconsistent. From him saying
it became a star,
to him saying it fused, from him saying
they fused and created an asteroid. These statements were made at different points in time (The Mega Weapon becoming a star coming first on September 5th, 2016, The first fusion statement coming on October 10th, 2016 and the final statement coming on November 6th, 2016) and would contradict each other. Which is to say, we really don't know what happened after they left the Ninja and Garmadon in the volcano. If the Golden Weapon made the Mega Weapon explode and make a star, then it wouldn't be flat 4-C as it was the combination of the power of Four Weapons and another Four Weapons with the Mega Weapon. The original four also couldn’t be comparable to it since they were in the golden blob state in season 3, meaning they couldn’t handle the full power of its creation if true.