With OP-14 and OP-15 cards in the format, the meta has diversified
It's because certain cards can be too powerful and unbalance the game
While there may be other cards with similar effects, Donna Noble's unique combination of abilities and synergy with the Doctor make her a strong contender for inclusion in decks looking to apply early pressure and maintain board presence
Many decks within Blue can use their effects to trash Digivolution cards, helping you trigger the draw from Upamon easily, but just as many as source-stripping effects that Blue has, there are as many decks that like to hard play Digimon rather than Digivolve, meaning Upamon will, most of the time, be live
It is extremely long
Exodia, the Forbidden One has a pretty measly 1,000 ATK and DEF, but if you have all the Forbidden One cards in your hand, you automatically win the game