they are starting to get a bit over their heads...
at first we had robots and a evil corp(dragon ball)
then an alien race invades earth and we got a space traveling adventure (freezer saga)
then a time traveling adventure (cell saga)
then a weird as fuck evil alien...
after that we started fighting gods, and a multi verse.
but now we are fighting gods of a different multi verse at a different time line :\ its like a cluster fuck of all the plot lines possibles... the worse that can happen is that black is using past goku's father body or future goku's son (goten) body...
so from what i understand, zamasu is in charge of universe 10 earth's planet, and after he fought an alien living in earth from an alternate universe he decided that all humans in all universes are dangerous and should be exterminated... he might as well paint his own face and call himself the joker because he is insane as fuck...
regarding the fight, it seem that zamasu was calmer and fought with his brain but still got overwhelmed by the sheer power and persistence of goku.
also there seems to still be an open door for retribution for this new kaioshin, not for the future one but for the present one, seeming like "his ki was different" as to "his ki wasnt evil yet"