You can find the regular Japanese Mystical Archive cards in Japanese Play Boosters and Japanese and non-Japanese Collector Boosters, and the silver scroll foil Japanese Mystical Archive cards, which can only be found in Collector Boosters
Burn and damage have always been reds bread and butter, but because its had to be balanced for competitive duel formats, its efficacy pretty much evaporates in the face of multiple opponents with double the starting life
If you do that, you fill graveyards very quickly, and that can be your win condition via mill or part of your graveyard strategy
Shadow Puppeteers, while expensive, does provide a ton of value
For example it was easier to reconstruct the commons sheet for Skyridge (73 different commons) than for Neo Revelation (20 commons)
Luis looks forlornly at his remaining two Elvish Mystics, and never plays them the rest of the game