Just a thought.. may be this (betrayal of love.. remember KT said she wants Eku.. yayayaya.. she did not mean Eku.. .but Eku doesnt know na??) could be a reason adding to the whole Eklavya turning negative.. I mean we all know that once he comes to know Tulsi killed his beloved dad.. he's going to go mad in rage.. So he may feel he's been betrayed by the two ppl he really loves and respects.. KT and Tulsi... prompting him to turn into a revenge seeking villian
So if KT were to be involved with Eku.. that wont work out, since M-T are supposed to be Ram-Sita ;)))) KT's beau has to be super positive just like Mihir ..