Thanks Subashini As to why they did not opt for the Mukund angle rather build a new character and that too so clumsily, I have my theory which could be completely wrong.
If I recollect correctly, Sultan was supposed to make an entry around November. At the time he was touted as an antagonist. Suddenly they back tracked and brought back Ballu instead. I think this could be because what happened in another popular show - IPK. there the show started off with a wide cast but then centred around the lead pair. They did not cultivate a parallel lead. The actor playing the male lead wanted to try greener pastures and quit. They were planning to get another male character for the female lead to pull on the show but the fierce fan backlash made them reconsider and the show was shut down, co-incidentally in November.
Now if they were to introduce Sultan as an antagonist they could well face a situation in future when VD could quit for better prospects, taking a cue from his fellow actor (VD may not quit at all but then the PH and channel could have wanted to have a parallel lead to meet such exigiencies),. Having in place a parallel lead who develops a soft corner for the heroine would have its advantages because there would be a fanbase for that parallel lead to fall back if the lead quits. The story then can be made to revolve around the heroine and the parallel leadd.
I think they had to work out Sultan's character again and hence used Ballu to fill the gap. Why Sultan? They could have used Mukund to create the third angle but then they knew Madhu-Mukund did not click the first time around. They needed a hatta khatta guy who can give takkar to RK (It is another matter many of us did not warm up to him because of the clunky nature in which he was built). Sultan was brought in and they deliberately kept misleading fans. They succeeded in creating two fanbases by bringing RK down several notches even as they skyrocked Sultan to the top. So their fallback is in place should they need it later to keep the show on for 1000 episodes. It is another matter that as long as VD continues to play RK so well and remains onscreen, they wouldn't dare go in for a full fledged Sulbala track for they know that Rishbala fans far outnumber Sulbala fans..
It is 12.45 a,m. as I am typing this so it could be utter nonsense of a sleep deprived maniac.