Pathogen: Bystander Gatherer

Inari created a special pathogen that is designed toward passively gathering natural energy while it has been infused into a normal ninjutsu, which has the effect of turning any ninjutsu that Inari casts into an actual sage art technique without being a sage himself. Since the natural energy is gathered into the jutsu itself and not Inari, he doesn't require any actual training as a sage in order to maintain the jutsu. Even without being an actual user of senjutsu, his techniques would carry sage chakra in them simply because the pathogen would passively be gathering it while the ninjutsu has been unleashed.