>>37123098Did this for a romhack that'll never get done, so prepare for autism.
They represent the cycle of things, end to the beginning, beginning to the end. Latias is the former, and has the ability to alter itself to suit reality (invisibility, change forms and such), whereas Latios represents the latter, and can alter reality to suit itself (that illusion garden place and such).
The Soul Dew contains the memories of all past Lati@s, and is how they are powered up, via shared experience.
This satisfies their abilities in the movie, and explains the cryptic messages at Southern Island "Those whose memories fade seek to carve them into their hearts. All dreams are but another reality. Never forget." Or, at least, goes with the theme.