Union Arena's Attack on Titan release arrived in 2025 as a pivotal set for the trading card game, bringing one of anime's most iconic series into the competitive TCG landscape. The set captured the franchise at peak cultural relevance, drawing longtime fans and newcomers alike to the Union Arena ecosystem during a period of strong anime card game growth. Eren Jaeger stands as a central figure in this set—the protagonist whose internal conflict and evolving power drive the narrative. This rare version presents the character in a compelling way that resonates with collectors seeking key character representations. Eren cards from inaugural sets tend to hold particular appeal for those building complete Attack on Titan collections or pursuing meaningful character portraits.