What happens if you KO Uxie and Mesprit Can you re-battle them?

While it is true that in most of the Pokemon games most of the legendaries do not reappear, in Pokemon Platinum it was introduced that many of that games Legendary Pokemon would in fact regenerate or reappear, even after being defeated. Most of these Pokemon are stated to have the condition to reappear automatically after you beat the elite four and champion and get entered into the hall of fame and will do so until caught*. I'm unsure as to whether this is true for any of the legendaries in Pokemon HeartGold or SoulSilver

*Cited from the Offical Pokemon Platinum Strategy Guide, though not worded exactly as present in there