|Pohatu enters The Cave.|
The Cave is not of our invention, rather, it is an invention of our older brother/s, back when they were into Bionicles. I can even trace it back to the year 2003, as that is when they got their first Toa Nuva.
So what is The Cave? Short answer, it is the explanation for everything. Long answer, it is, when we played with our Bionicle sets, how we could justify having two Tahus, two Pohatus, Two Vakamas, ect ect.
The cave works as thus: A single Toa (Let's say, Pohatu), walks in The Cave. A flash of light happens, then a newer, revamped version, int his case, Pohatu Nuva, emerges. Someplace else, the old versions appears. Early days had the early version appear with an infected Kanohi, or Krana, or some sort of mind control. Then we had another bad guy until we could be rescued. Villains were a bit short in those days.
The Cave disappeared for many years, probably around the time we realized we didn't have to use all of our doubles in games. But recently it has re-emerged. Because, basically, it can solve any problem Bionicle can through at us.
(On a side note, I drew that picture in an hour or so. Not bad, for being only my second ever Bionicle art work. And the first barely counts.)