"Centur-Ion Phalanx" (banishes 1 monster, then can revive a Synchro but it loses 1500 ATK) and "Centur-Ion True Awakening" (omni-negate, sending one face-up monster in the Spell/Trap Zone as cost) are archetypal Trap cards, helping create interactions without Summoning too much (playing around cards like "Nibiru, the Primal Being" and the "Mulcharmy" monsters)
This means that the value of X may be different than you had hoped when attackers were declared if attacking creatures have left the battlefield or their power has changed
These packs are based around a theme, which is typically 1 or more archetypes, and pull from a featured card pool of 40 or fewer cards to help build a Deck based around that theme, in addition to several cards from the Master Pack
Full-Art Custom Forest This is a beautiful and serene Forest alter done by Reddit user and popular MTG alter creator Snikrot914
That being said, I think the reasons for a card being banned can be broken down into two main categories: A card is too powerful on its own and almost every deck has to have it to be good
Number: SDRR-EN029