jiroxy ball...
After you beat the elite four and the galactic biulding
You have two chances to catch Mesprit. If you accidentally make it faint both times, you can't catch it anymore. If you made Mesprit faint once, find it, trap it, lower its hp to 1 using false swipe (you should have gotten the TM), let it escape, then encounter it again and use a quick ball.
A Master Ball
You catch Mesprit in HeartGold in Route 48 on either Mondays and/or Wednesdays while listening to DJ Ben's Marching Band. Or at least I think! Hope I helped^_^ ~ Kaede Nagase.
Mesprit roams Sinnoh.
Mesprit Azelf Uxie Palkia
Catch better Pokemon
you can catch mesprit after the championship on the wild >
Yes you can. later in the game Latias (or latios depending on which game you have) is attainable. Like mesprit in Pokemon diamond and pearl and like mesprit, latias and latios tend to flee.
no
You need the marking map you used to catch mesprit You need the marking map you used to catch mesprit
after you beat the elite four and you catch creselia and mesprit
the way you catch azelf mesprit and uxie.
anywhere
chase it down
=no=