Sylvans and SSA are certainly tier 0.
These decks have a lack of counterplay.
Tbh players with those decks reaching KoG should get a big F on their KoG logo, pointing out that it was free skillwise.
Actuallu, SSA has 2 counters (cosmic cyclone and Anti-magic arrows) that can be used in many decks. But, SSA has the possibility to search its key cards, and this is vantajous.
AMA prevents SSA from activating, meaning you can destroy their monsters via battle or even destroy SSA//umi itself via monster effect like D-hero celestial.
Anonymous
Simon
