Why is it, that every movie where a good guy and bad guy are about to have a fight to the death, the bad guy always offers a chance for the good guy to turn to the bad side? The good guy always declines, and then offers the bad guy a chance to go good. Did Desann really expect Kyle to turn at the end? Then Kyle has 2 b all like "Even after all this pain, its not 2 late, come, join US". Did he expect desann to say something like "Kyle, you are right, I have made a bad choice in my life, and I am going to give up all this power to begin re-training with some paddies, some of which I have personally killed. I wish to surrender to the light side.". I dont think so. If n e thing, hthe paddies would be just a little pissed for killing next to all of the jedi in the invasion, and manipulating the force to give to non-force sensitive troopers.
Kyle was just messing it may have worked he just thought it may change the conversation a bit thats what kyle is like he makes jokes like that!
Also When Obi-wan thought vader, vader never asked obi-wan to join the darkside did he?
No Vader Never Asked Obi, But Until Ep3 Comes We may Never Know. And You May Perhaps Be Right About Kyle.
Most likely to alleviate his conscience, for Kyle. Jedi only kill when their is no other option, so he at least had to ask so he could know that he did the right thing.
For Desann, I think it was more of a taunt--he is insinuating that he believes Kyle is weak enough that he might actually consider such an offer.