After battling Dialga/Palkia, go to Lake Valor and surf to the centre.
Enter the cave and you should see Mesprit. Go up to it and press A, and it will flee.
Then look on the bottom screen of your DS and go to the app which finds these Pokemon (It looks like an empty map).
Walk a few steps and then it should show a flashing face. If you fly to that place, the Pokemon will move somewhere else so it is best to ride your bike. Good luck catching it!
After the Spear Pillar Events, Surf to the centre of Lake Verity and enter the cave. I strongly reccommend saving before you battle.
simple.... your poke's slower than mespirit
Emuritto is the Japanese name for Mespirit. So emuritto is Mespirit, to answer your question. :P
nooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
Sorry, but no.
catch them from there lakes then mespirit will run away so maybe use a materball
weaken mespirit a bit and use dusk and quick balls you might be able to use heal balls on it
After you've released Uxie, Mespirit and Azelf from Team Galatic HQ, go to Verity Lake. Surf across to the cave. Inside you'll see Mespirit. Talk to it. After it runs away, it will be roaming the Sinnoh.
Here is a walkthrough on how to catch Mespirit: http://www.youtube.com/watch?v=ee1-2AU0k6w Do exactly what he tells you to do!
for example:this is how you get mespirit: so after you beat it you beat the game you go back to mespirit {its in the same place} you battle it. if you win it mespirit will ask to be on your team. say yes and TA DA!!!!!!!! mespirit is on your team. same with dialga and palkia and some other legendaries. some will just ask to be on your team.
no
Psiycic