Outside of introducing new cards, Shadows in Valhalla has some amazing competitive reprints for players, including: Mermail Abyssmegalo, Invoked Mechaba, Windwitch Ice Bell, Twin Twisters, Shaddoll Fusion, Gem-Knight Seraphinite, Aleister the Invoker, El Shaddoll Winda, Cyberdark Impact, and, the most important reprint, Ash Blossom & Joyous Spring
People grading modern including my brother are experiencing odd bum grades in amongst their 9s and mostly 10s to keep the overall percentages from being even higher
Historically blue has outsourced most of its finishers in counter based control decks but more recently seems not to need to so much
Another huge boon for Steel in Archazias Island is Belle Apprentice Inventor
Fortunately, there is one Stage 1 Pokmon that allowed this attack to be significantly more efficient, and Metang was a crucial part of these incredible meta decks