Orochimaru versus Tobirama

[USSJ Future Trunks]

tell me what stops Tobirama from keeping beheading Orochimaru with his ThunderGodSlash until Oro runs out of chakra because of the overusage of his body replacement regen (and please don't say Oro can outlast a Senju because it would give me cance

the only senjus with massive chakra levels were hashirama and sage's younger son. it wasnt a trait everyone had, especially this far down the diluted bloodline. itd be like every uchiha having rinnegan cos madara did.
and by showings, tobirama hasnt been all that special chakra wise. oro had enough to fight 4 tails kyuubi/two sannin head on in a sick state and no arms. tobirama died to 20 fodder at full power

tell me how can Orochimaru touch someone who can just FTG away whenever he wants to...

how did kinkaku and ginkaku leave tobirama in near death if he could teleport away? how did 20 jounins catch and kill him if he was luring them away with FTG? how did madara last that long if he was constantly in battle with tobirama?