Thats has nothing to do with the facts. More rebels have been killed by ISIS than PYD soldiers. The fighting has been more widespread between ISIS and rebels. 

 Also lets stick to what sources say.  

 Syria's three way war http://www.independent.co.uk/news/world/middle-east/syrias-threeway-war-free-syrian-army-rebels-fight-the-regime-and-now-the-islamists-9052660.html 

 New syrian war front http://news.yahoo.com/jihadists-kill-31-rebels-syria-172021964.html