You can't you only get one chance. you should save before battling them.
*REAL ANSWER *
you have to wait a couple of days for them to go back to their cave. there is no way they can just not be there anymore. that's the point of Pokemon!
you weaken it then use a ultra ball and a little chance of getting it or u use a master ball
to catch the fog
Catch the Brass Ring was created on 2007-09-04.
to catch the fog
yes you can
you will die
No, Mespirit, Uxie, Azelf, and Giratina have no gender. Also Dialga, Palkia, and Giratina created Mespirit, Uxie, and Azelf.
catch them from there lakes then mespirit will run away so maybe use a materball
Uxie Azlef and Mespirit don't catch in you have to get the membership card from mystery gift by Nintendo wifi but its not avalible anymore
Psiycic
you can find uxie,azelf,and mespirit plz people say thank you to me ^_^
Yes, they appear when dialga appears and stop him from ending the world. which then allows you to catch dialga. afterwards mespirit azelf and uxie can be caught at each of the lakes, mespirit will vanish and will tease you throughout the rest of the game.
You can catch all of them, but if you're saying which one you should catch with a masterball, I would save it for Diagla or Palkia.
hmmm why dont you catch the other legendaries? heatran, mespirit, uxie, azelf, cresselia...u know...
There isn't one.
Dialga, Giratina, Heatran, Mespirit, Uxie, Azelf, Regigigas, Rotom, Cresselia,
I found it dificult but mespirit when he faints will just teliport to another place and for uxie and azelf you need to defeat the elite four and Cynthia then you can face them again.
Uxie, Mespirit, and Azelf are unavailable in Pokemon SoulSilver. They can, however, be traded from a Diamond, Pearl, or Platinum game, or transferred from a Gen III game.