Back around 2002, some of the Guardians players online decided that they wanted to create the proposed Seven Seas expansion, which never got past the naming stage. (There was a name for an expansion, and that's it.)
As this progressed, many of the cards I suggested on the list were made into cards, and they were better at it than I am.
For those who want to see them all right now, the rules and cards can be found at Phil, the Bar Fly's website.
On the off chance that his site ever disappears, I'm going to import some of my cards over here, now that there are people actually visiting this site.
Elixir of Energy Hand Magic Item, Up 12,
Play after any primary matchup is resolved. Turn any face-up channeler face down again. This card may not be removed from the discard pile. (Artwork: Giancola, Text: C.J. Burke, Design: Cath)
I originally made a comment about Champs, the Wonder Dog, which is why this card couldn't be removed from the discard pile. It might have made more sense to say, "after playing, remove this card from the game".