The double-headed Nillious main motive in brawls is to kill - not to win. He does not like fighting as a team with his partner, Nillious is out to satisfy only himself. He likes to go rogue. Each head has its own personality & ability. Untamable & vicious, Magnus has his hands full keeping Nillious in line.
Titan Nillious is the first super evolved Bakugan seen in Battle Planet.
Titan Nillious is the first evolved Bakugan to gain two physical beings in Battle Planet. Preyas II also has two forms that it switches between, and it was the first Bakugan to do so, making Titan Nillious the second.