The Basics of Gokaiger

I am inspired to do a similar entry from Henshin Grid's entry "The Rules of Gokaiger" and here's writing on the show itself:

It's based on the Legend War. Yup so we won't be seeing the team going back and forth in different time periods. Hmmm... so did those dead warriors temporarily revive? As TheChick said to me saying, "Apparently, the legend war took place in the past, and this series takes place in a very near future. The warriors could have used time travel, magic, or replacements for fallen soldiers or whatnot. Don't think too much of it, because continuity conundrums will give you a headache and stop you from enjoying the show." However if she wishes to do more discussions, email would be better.

So they're not from Earth which was already established since episode one. I believe Power Rangers had a strong impact here. The idea was incorporated into Sentai in Goseiger but the idea of aliens as rangers came from Power Rangers with the underrated Alien Rangers' series which was a failed concept due to bad writing.

There are the transformation keys- colors DO NOT restrict them from becoming the other heroes (can't help but use Luca as the model). In group transformations it's more restrictive though like how the blue ranger dons a modified version of a female blue ranger suit. For example, when the Gokaigers become the Jetmen, blue swallow becomes male and yellow owl becomes female.

Past heroes will return and perhaps all of them will appear without their powers.