The series covers a large range of effects, and is largely tied together by their artwork, which form a narrative. Several other cards that are not part of this series and have dissimilar effects to the cards in this series (such as the "Huge Revolution" series and "Rock Bombardment") also depict parts of the same storyline.
It is very difficult to make a Deck purely made of or centered around "Royal" cards. However, many staple cards are in this series, most of which have anti-meta effects.
These cards all depict an Emperor and his castle or revolutionaries trying to overthrow the Emperor. It's worth noticing that the Emperor is called "Tyrant" on later trap cards, implying that he probably started to behave as such. That would explain his later actions and the need for a revolution. Some of these cards are references to "The Emperor's New Clothes".