Sein Pam is the older twin brother of Lewin Pam.
Like his brother, he is seen being somewhat a jerk, as they tease Dan and call him a chicken. By the end of Twin Attack, they seemed to understand why Dan tried to stop them from entering Bakugan Interspace, and are nicer and feel a bit ashamed of the way they acted.
Sein first appeared in Twin Attack along with his younger twin brother, Lewin Pam. Dan and Jake tell them not to go into Bakugan Interspace because it was invaded, but they ignored the warnings and went into Interspace, where they were hypnotized by Kazarina alongside others off-screen.
They later battle Dan and Jake under the hypnosis, but they easily lost and snapped out of it.
Bakugan: Gundalian Invaders