Do Mesprit,Azelf,Uxie and Dialga respawn at one point?

Question

I accidentally defeated Azelf without saving before the battle.

Answer 1

I'm really sorry, but they can't respawn in D/P. They can in Platinum, however. So, you can't get Azelf again, unless you can go to your last save point. It is after the Elite four and Champion in Pt.

Hope I helped!

Answer 2

Only in Platinum would they respawn after defeating the Elite Four.