His powers as the Thunder Stranger are;
Falling Thunder Deathbed: His sword becomes a lightning conductor and shoots lightning
Sarai was first seen attacking the royal ship. He seem to fallen in love with Mizuno and saying he loves her even when he is rejeated seveal time. When Mizuno was being eaten by Lalzone, his will to save her made the thunder-stone accepts him and he became "Thunder stranger Sarai". He and Mizuno are seen as a couple in volume 3.