Some might be revived when new sets revisit the same plane or theme, or appear in supplemental products which arent limited to a narrow mechanical palette
If you are an active player, you may want to have your most used type first, followed by your second most used type, and so on
If you choose to transform it, you flip the card over, revealing its transformed side, "Azcanta, the Sunken Ruin." Azcanta, the Sunken Ruin now functions as a legendary land with its own abilities, and you can tap it for U mana or use its abilities as appropriate
Triskaidekaphile is an old favourite, but the utterly adorable and delightfully fun to say Twenty-Toed Toad is entirely new
Shiny basically just means a different color scheme than how Pokemon typically appear
Whats really impressive about this particular product is quite how much effort has been put into making these decks viable against modern decks