nagatos got no katons. so kabuto should be able to control the battlefield. to avoid attacks he hides underground or uses orochimaru/karin cells to regenerate.
orochimaru's leech all creation: attack prevention technique enables kabuto to merge with the rocks in chibaku tensei.
nagato has never seen tayuya before so he will be caught off guard by a genjutsu that incredible.
white rage can paralyse rinnegan. kabuto is also capable of producing a sleep genjutsu to distract nagato from what hes really doing. bone kekkei genkia isnt really chakra so preta path cant absorb it and its rootted in the ground so ST is useless.
using jirobo kabuto opens up a fissure and locks cerberus inside.
using SM sensing he can see where the chameleon is and kills it.
manda II takes out the rest of the summons and holds off gedo mazo should nagato summon it. if nagato uses the soul dragon, he will be left crippled anyway and kabuto > hanzo in speed so its really no problem for him.