Union Arena's Attack on Titan release in 2025 marked a significant moment for anime trading cards, bringing Wit Studio's beloved series into a competitive TCG framework. The set captured renewed interest in the franchise during a pivotal period for anime card games, establishing itself alongside other major properties in the Union Arena ecosystem. Annie Leonhart's Female Titan form represents one of the series' most compelling antagonists, and this Super Rare treatment showcases her dual nature as both soldier and monster. Collectors are drawn to cards depicting her titan transformation, as Annie remains central to the narrative's emotional core and mystery.