Chakra has a mass therefore is affected by gravity obviously. We know this because Onoki made Susanoo Clones heavy using Earth Heavy Rock Jutsu, which uses gravity to dictate the mass of the desired target, and in Onoki's case was make them heavy. Bansho Tenin manipulates the existing gravity (earth's) to either pull the target to the user or in telekinesis manner. Susanoo is therefore can be pulled, if Bansho Tenin was used on it.Susanoo doesn't have a mass
This misconception is false too for the fact we've seen Susanoo physically separated from the user multiple times in the manga. Susanoo isn't actually physically merged with the user, but is mentally linked and manifested in 360 degree manner. It can be separated, however; we've seen this with Gaara:If Nagato/Pain pulls Susanoo via Bansho Tenin, Susanoo also follows the user
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Bansho Tenin is different from the sand, and would be superior in that case because Nagato has shown to pinpoint whatever target he wants to pulls via Bansho Tenin. Unlike a sand forcibly pulling a target, Bansho Ten'n utilizes gravity to pull something and Nagato has shown to pinpoint specifically, and no thing in the universe is resistant to gravity, not even light.
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Susanoo would lose to Bansho Tenin because the user can be pulled away like Gaara did, and Susanoo would be deactivated immediately.
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