[GAMEPLAY] How does Jhin work with Assassin Keystone?

This had me thinking... how exactly does the assassin's keystone work with jhin? If he ults and allies are nearby, does it not cancel assassins because they're no where near the bullets hitting the targets?

Or what if they're standing by the enemies, you're far away, and ult-gank their lane.. does assassins still apply or because allies are nearby the enemies you're shooting does it cancel?