The Legend of Heroes: Trails of Cold Steel IV (CS4), are a specific feature designed to upgrade character abilities through unique combat challenges. Feature Overview: Trial Chests
She clicked because she was sleep-deprived and because, somewhere deep in her gut, she already knew what CS4 stood for: cs4 trial new
: Each chest specifies the exact characters that must be in your active party to attempt the challenge. The Legend of Heroes: Trails of Cold Steel