what is the purpose of a side deck in yugioh Transition Sidedecking for Goat Format

So as a lot of you know, Konami has decided to do an anniversary Legend of Blue Eyes reprint along with many of the other original sets, but with a stamp on the card

Each booster pack includes 15 cards to help make your deck better, whatever way you play.

1 Aegis Angel

Ive been trying to find information on older Pokmon cards printed in Portuguese, and whether there were any differences between cards printed for distribution in Portugal versus Brazil

YuGiOh Master Duel forbidden cards might limit your deck-building potential, but they won't stay banned forever.

Specialized Application: The card centering tool is suitable for Pokemon cards