In showdown it's easy to follow. In normal matches and tournaments, wait until you get killed by it so you know what name has got it, then go after them with either eclipse, surge, seeker, nomad, mimicker, redox, or blizzfrost and it's an easy kill if you wait for its ability to end when it's fighting one of your teamates,
And put either compound beams, revokers, burrow beams, charge rockets, geminis, or even stormracks on those mech I mentioned and it's easy kills once you stalk it and wait for the ability to be over,
In normal matches if your not maxed then you shouldn't see any voidghosts that are maxed so they'll only have one ability to use, but tournaments and showdown you'll see them an thats plariums fault for not fixing match making, it's not the mech itself, it performs as it should at maxed level
But yeah anyway just stalk it and go after it with any combo you can come up with out of those mech and weapons, compounds are definitely more effective if your mech aren't maxed