TV-Series
Description
Liena Grace Vincent is the twin sister of Gray Michael Vincent. Orphaned as children in Wintoon village, she and Gray were raised by local townspeople. Liena has blonde hair, green eyes, stands 150 cm tall, weighs 38 kg, and was born on April 30 with blood type AB. In the anime, she wears a maroon jumpsuit, a red jacket, and white fingerless gloves.

She demonstrates kindness, reasonableness, and a strong sense of responsibility, often prioritizing others. She shares an extremely close bond with Gray, symbolized by matching winged lockets, and serves as his primary motivation. The Shadow Alliance kidnapped her to force Gray into their service. Held captive, she was brainwashed by Ababa, adopting the identity "Sigma" and wearing a mask and cape. As Sigma, she wielded the B-Daman Garnet Wind with yellow B-DaBalls matching her hair. Using aggressive tactics, she defeated Terry McScotty in the IBA Winners Tournament and later battled Yamato Delgado. Yamato freed her mind with his Spinning Cobalt Power Blast.

Rescued, Liena rejoined Gray and his allies, supporting their fight against the Shadow Alliance. She forfeited her tournament spot to enable Gray's rematch with Yamato and later assisted in defending Yamato during Cobalt Saber's completion. When Gray and Yamato confronted the Neo Shadow Alliance, she was left behind for safety but chose to join Mie and Armada in searching for them.

In the "Fire Spirits!" storyline, Liena actively sought her own Strike Shot. She encountered Gray during his acquisition of the Speed Shot and intervened in his battle against Haja. Though defeated, her action spurred Gray to victory. She participated in challenges like the Ultimate Strike at a B-Coliseum and teamed with Yamato and Tommi to continue her search. She also competed in a Battle Royal Hockey match, eliminating Jinbee and engaging Gray directly before the match was disrupted. This period shows her seeking greater independence and battlefield participation.

Beyond her brother, Liena maintains significant relationships, including a supportive dynamic with Yamato and a respectful connection with Enjyu after his change of allegiance. She attracts attention from characters like Sigma and Wen Yong Fa but remains focused on her goals. Her development transitions from a damsel-in-distress to an active participant in battles and team strategies.