...I guess it's not over.
The Circles is the edge of The True Arena, It contains another circle but no more inside of it. Each circle contains an invisible portal to a battle arena.
The String is the 2nd layer of The True Arena and almost the last. It contains lots of Antiverses that have been expanded. It is made out of Antimatter and then inside it contains Cubium (3052th element) that is a liquid. Also, there are a few The Barrier of Realities in there too.
The Core is A The Barrier of Reality covered in Criranium (4052th element) and is a liquid too. But the Barrier has a really strong force so it makes a Sphere. Other parts also hold barriers, but the middle one is where The Bubble Blower is and thus is more special.