Those Who Were Left Behind
Ruuji is attacked by a woman called Gaball, seeking revenge for her dead lover Dinga, who was part of Ra Kan's resistance army. Ron convinces her to take out her anger in a Zoid battle - her Brastle Tiger vs Ruuji's Murasame Liger. During the battle, a group of Bio-Zoids show up and Ruuji and Gaball are pushed into a trap. Ron and Mii come to their rescue, and Murasame transforms into Hayate Liger to finish the job.
Aired 06/11/2005EP 31 - Those Who Were Left Behind
Zoids Genesis
Natural disasters have devastated planet Zi, killing off almost all life. A thousand years later humans have gradually re-established civilization, salvaging ancient Zoids through diving and mining efforts. In a village whose most previous item is a giant sword which they worship as a holy symbol. A teenage boy discovers an ancient Liger-type Zoid while on a deep water salvage operation. Suddenly the village is attacked by skeletal Bio-Zoids intent on stealing a powerful generator located in the village. Our teenage hero awakens the Liger and discovers that the towns sacred sword is the Ligers weapon, together they fight off the mysterious Bio-Zoids. At least for now...
(Source: AniDB)