U NEED POKETCH APP MESPRIT IS STILL IN CAVE YEYZ
Instead of flying to the nearest city, which makes it run away, walk or bike to its icon on poketch app Marker Map and look around in the nearest patch of tall grass. Mesprit often runs away, so be careful!
Go and talk to the owner of poketch in poketch company's building he will install the marking map app in your poketch
Mesprit moves around the world at random so it could potentially be anywhere after it runs away. To find where he is, use the map on the Poketch.
its a poketch app.
U NEED POKETCH APP MESPRIT IS STILL IN CAVE YEYZ
Get the PokeMarker Poketch app from Jublife City Poketch building. It will show you where Mesprit is.
Visit Mesprit at Lake Verity (near the starting town) at the cave in the centre. It will fly off, you should be able to track it with your Pokegear.
Refresh/Change Poketch App then go back to the same poketch app and the dot should be gone!
OK here we go. If you have the "marking map" poketch app (the one with the star, heart, etc.), you'll be able to track mesprit's movements. My suggestion is to stay in Jubilife, and take the road up repeatedly. The mesprit will begin to patternize, and appear north of Jublife
Some of the cities or towns are more important than others and those locations are given red squares. The lesser but still important places are either blue dots or blue squares. Also if Mesprit has been released the red dot on the map will be Mesprit's location. You can also track it using the map application on the Poketch.
you use the marking map on the poketch which you get in the poketch building after you beat the third gym. and you catch them by chasing them on the marking map like mesprit. i suggest using the move mean look which golbat and haunter learn
after you save the three of them from team galactic, go to the cavern and see mesprit. it will leave. It will now rome around the region and you have to track it down using the poketch app "marking map" and catch it in the grass with the normal wild pokemon.
Instead of flying to the nearest city, which makes it run away, walk or bike to its icon on poketch app Marker Map and look around in the nearest patch of tall grass. Mesprit often runs away, so be careful!
Here is a guide to tell you how to get all the poketch apps:http://www.serebii.net/platinum/poketch.shtml
Go and talk to the owner of poketch in poketch company's building he will install the marking map app in your poketch
After going to the little island in lake Verity, Mesprit will fly off. Use the Map app on the Poketch. There will be a little face. That is where Mesprit is. If you fing him on the grass in that route, be careful not to knock him out. He will run off as his move. Make sure to use a faster Pokemon.