Omni Lord

"Omni Lord" ( Kakuō) is a keyword that allows a card to be used in decks with any flag. However, if the card and the flag are of different worlds (even if it is a special flag), only up to one copy of that card can be used in the deck.

It appears marked by the text: 

Dragon World

 * Fifth Omni Dragon Lord, Tenbu

Trivia

 * This is the first keyword enclosed within a white box rather than red, but still it is considered a keyword.