“How is the overman different from say kalki or Jesus”. It all depends on how you view Kalki or Jesus. Let’s use Jesus. Do you use Jesus as a substitute for being good or perfect? Do you go to church every Sunday to ask for forgiveness for being imperfect?
The overman doesn’t need to follow in that sense. The overman takes responsibility for him/her self. The overman isn’t a replacement for Jesus, but perhaps, in a nietzsche sense, Jesus is an overman. Because Jesus accepts the consequences of his own purpose.
I know this sounds somewhat different than most interpret Neitszche as, or Jesus as, but it is inclusive. Did Jesus not want everyone to be like him and not just follow him? Nieszche argues Jesus, “as a child of god everybody is equal to everybody else”- twilight of the idols”
More reading
http://www.gutenberg.org/files/52263/52263-h/52263-h.htm section 41, etc.
I do realize it seems as though nietszche attacks “Jews”, but I do not feel the attack has anymore relevance than his attacks on German culture or Catholicism. It is merely an observation against people using others or majority’s or hiding behind imperfect ideologies.
Here is some more reading for those who enjoy knowing instead of understanding.
http://www.joeledmundanderson.com/nietzsches-ubermensch-vs-jesus-christ/