Level: This determines how difficult a monster is to summon
As a beginner seller, or someone who just wants to quickly offload a collection, eBay or Mercari may be your best bet, but it still doesnt hurt to be cautionary about listing upsells
As a good example, consider the resonance with Dungeons and Dragons
2 - Super Starslayer TY-PHON - Sky Crisis Super Starslayer TY-PHON - Sky Crisis, nicknamed by players as "anti-zeus", has a continuous effect that "disables" activated effects of monsters with more than 3000 ATK, which is incredibly useful to deal with a Divine Arsenal AA-ZEUS - Sky Thunder in the enemy board, or some of the main generic "boss monsters" in the game, such as Baronne de Fleur
Snow mana is generic by nature, but effects that would reduce a spell or ability by a generic mana do not affect Snow mana