While a four-mana 8/8 reach with evasion isn't exactly broken in Modern, and it is annoying that its backside's mana value is two, which means it dies to things like Fatal Push, March of Otherworldly Light, and Prismatic Ending, the opponent will lose the game super quickly if they don't have an immediate answer
Unlike many walkers locked into specific color combinations, Ugin rewards decks that can accelerate mana regardless of color identity
Each face may have abilities that allow the permanent to "transform," or turn over to its other face
I've found all the sellers incredibly helpful, even some as far as putting in an extra card that they think would fit the theme (happened more than once you know who you are Rob)
Like the other enduring cards, Enduring Courage returns as an enchantment after being destroyed, which this card is hardly phased by compared to other Glimmers, only being a 3/3 creature otherwise