This is not canon, but conclusions drawn from canon and logic on infinites...
Some things that should be considered...
- The Dimensional Labyrinth opened up access to infinite parallel realities.
- Due to the infinite nature of the labyrinth is why the anti-spirals expected the team Dai-Gurren to be stuck there forever. (Infinite number of parallel relaities, an Aleph 0 infinite)
- They got out anyway.
- The only way to counteract an infinite is with another infinite. (Especially useful is a higher tier infinite, such as an Aleph 1 infinite overpowering an Aleph 0)
- Spiral power seems to provide a feedback loop. People with strong spiral power around others with strong spiral power seem to get even stronger spiral power.
In the Dimensional Labyrinth, they encountered what most fans believe to be a ghost/image/memory/reincarnation of the "true" Kamina. However, it should be noted that each of these infinite universes had its own Kamina.
A concept to take into account... Kamina only died in the primary universe. His many variations were alive in the labyrinth. Each one of these by itself was not the prime Kamina, but between them, they had the traits of the prime Kamina.
This means, likely most had the desire to achieve the higher level than they were and would never be satisfied in that regard, and to break through any boundary. If one version of Kamina could reach a point to where he could break through from one dimension to the next, things get interesting. The fact that this manages to happen is evidenced from the way they're pulled by him back into the prime world, and a very prime-like Kamina is appearing nearing less primish Kaminas (Kaminai?).
Through this interaction, the core personality of the prime Kamina would re-emmerge due to the Prime Kamina's traits being the most shared traits (likely causing many Kaminas to gravitate towards the original ideal as they try to reach their ultimate potential), and they would discover the nature of the Labyrinth.
These prime-like Kaminas would, by their nature, increase his power by reaching out to the other Kaminas. And any Kamina he could reach would likely also learn this ability (through becoming stronger, learning technique, whatever). And in infinite realities, there would be infinite Kaminas attempting this. Upon knowing the anti-spirals created the Labryinth as a prison for freedom fighters, he would desire nothing more than to break that boundary, and seek them out.
Now, imagine... an infinite number of Kaminas, their spiral power feed-backing from an infinite number of other Kaminas, with enough presence to effectively search infinite realities and find every single original member of Dai-Gurren. That's infinite Kaminas, each with infinite spiral power.
Aleph 1 infinite achieved.
Although team Dai-Gurren may be limited in number, the dimensional Kamina would have no such limit, and be able to break them all out and give them energy to spare.
In a way, it would make sense, knowing the characters and the realities invoked, and would explain the reality-shattering power team Dai-Gurren achieved after being effectively decimated.
Although, I have to say, if my hypothesis is accurate, a side series about all these Kaminas and their journeys could be pretty interesting.