When you played Pokemon Omega Ruby and Alpha Sapphire, you may have used the DexNav app on your Pokedex, which points you in the direction of a certain Pokemon hidden around your location or find more of a Pokemon already in your Pokedex. Now in Pokemon Brilliant Diamond and Shining Pearl, you get the Vs. Seeker, which allows you to find, who else, other Pokemon Trainers.
The Vs. Seeker is a device that lets you know which Trainers want to battle with you. You can also use the device to determine which Trainer to avoid having a Pokemon battle with if you’re trying to speed things up in the main story mode. The only caveat is that it only works every 100 steps you take to charge its battery.
When you ride your bike to the end of Cycling Road, Lucas or Dawn (depending on which character you’re playing as) will run up to you and ask you to choose either their left hand or right hand. Whichever hand you choose, they will present you with the Vs. Seeker, along with a Dowsing Machine (that’s another guide).
From then on, the Vs. Seeker will tell you which Trainer will initiate a Pokemon battle by reacting with an exclamation mark (!). However, as previously mentioned, it can only be used every 100 steps you take to charge it. For example, if you walk towards a Hiker or a Lass Trainer and you use the Vs. Seeker once, their exclamation will pop up and give you an opportunity to engage in a Pokemon battle with them. If there are too many Trainers in the area and you try to use the Vs. Seeker a second time because you didn’t pay attention to who want to battle with you, you will have to take 100 more steps to get it working again. You must use it wisely.