Hello good day,
I have tried to recreate your blueprint but mine spawns the emitter on the right character.
I created this on the character blueprint.
Sorry I still haven’t got a clue on what is the problem. If you have any additional information would gladly help more.
You also said that the one who equips the weapon would spawn the emitter after clicking the SpecialAction button but in your blueprint, nothing is checking if the player currently equips the weapon