A new shiny Rotom and shiny Koffing will be released in S4a Shiny Star V! The set will be released on November 20th in Japan. Thanks to bangiras for the translations.
[D] Ascension: Search your deck for a card that evolves from this Pokemon and put it onto this Pokemon to evolve it. Then, shuffle your deck.
Weakness: Grass (x2)
Once during your turn, when you play this card from your hand onto your Bench, you may search your deck for up to 2 Item cards with “Rotom” in their name, reveal them, and put them in your hand. Then, shuffle your deck.
[L][C] Thundershock: 30 damage. Flip a coin, if heads the opponent’s Active Pokemon is now Paralyzed.
Weakness: Fighting (x2)
The cards will also appear in the set as regular non-Shiny cards, as shown below: