Trinityteam please help me

Hi

i ve got a big question:

So, I go a phase , here a npc , I attack this npc. Ok it’s good ,but the my problem this: A another player go to this phase but this player sees that(when i attack the npc)

How can i solve this ? (when the another npc go to this phase , the player doesn’t see me and the npc wasn’t attacked.)

Like the quest chains ( example: DK light of dawn quest, the dareon morgraine start a wp when i select her gossip menu,but when another player go to this phase the dareon wasn’t moved. Just only if we are in a party.)

Very,very thanks if you helped.