See through walls

Im tryin to make a mod about super powers. I need to do something like see throught walls. All i wanna do is if player have "custom x effect", they can see through walls. I know i can do that with just giving other mobs glow effect. But this method not works on multiplayer. All players can see glowing mobs. But all i wanna do is if you dont have "custom x effect", you cant see glowing mobs. Can you guys help me about how to do this?