Union Arena represents Bandai's ambitious trading card game system designed to unite multiple anime properties under a single gameplay umbrella. The Attack on Titan release brought beloved characters from the series into the TCG format during the franchise's enduring popularity. These early 2025 releases captured the game in its formative period, making the set a snapshot of Union Arena's foundation and an entry point for both anime fans and card collectors exploring this newer competitive landscape. Eren Jaeger as a Super Rare card embodies the protagonist's central role within Attack on Titan's narrative. Collectors seek this card for its prominent character representation and the artwork's depiction of one of anime's most iconic figures. As a higher rarity from the set's release window, it remains a cornerstone pull for fans building collections around the series' core cast.