[flashflash account]

To clarify order of operations:
The roleblocker will always act first, meaning they can successfully block the hider's action in this setup.
The hider will act before the nightkill, meaning as long as the hider is not roleblocked, they receive the nightkill immunity as per the role.
If the roleblocker and the hider target the same player, the roleblock goes through before the hider is hidden, meaning the hider will not be affected by the roleblock in this scenario, but would still be affected by a nightkill on the third player as per the role.