On the frost side you get a copy for the same mana and ability, save that it keeps its Spirit type, which is unusual since most Clones have the Shapeshifter type
effect: When a monster declares an attack, you can negate that attack, destroy a targeted card on the field and Set a non-Labrynth Trap from your hand or Deck
While I think Pluto is a little too beefy in the Amber and Emerald deck, with a Bodyguard power that means I seem to always be facing him late in games, the general balance of the cards was fine
Negotiating effectively is an acquired skill that comes from practice, so don't be afraid to try it, learn it, and perfect it
Gem-Knight Garnet found a home inside Light decks since you can use Brilliant Fusion to use it as material from the deck