"Next time the effect would apply" - rule clarification
Looking for clarification on this type of rule. Example:
>Unstoppable Mark: One per activation, before attacking, pick one enemy unit within 18" in line of sight, which friendly units get Unstoppable against once (next time the effect would apply).
>Unstoppable: Ignores Regeneration, and ignores all negative modifiers to this weapon
Does this mean:
- Only the next (one) unit to attack receives the buff, or
- Each friendly unit, the next time they attack, they receive the buff.
I find any rule written in this way to be confusing and not as clear as they could be.
Help?