Here is your answer:1- Go to this link: http://www.playdota.com/guides/loveyuerus-guide-to-shadow-fiend2- Search this "quick-raze" via 'Ctrl+F' .3- Read that article for more info.
well you will raze faster by cancelling animation wich is double clicking de raze button,try it yourself click make the z x c clicking once in it button and time it then make it clicking in it twice i never tried this but i feel like it goes quiker,and i think it does more damge if you make the razes consectivaly, i dont know if it is either because of the creeps regen or because razes do a very tiny bit more dammage because until 30 min in the game 2 razes clear the mellee creeps but after 30 min or 40 the creeps gain more life and if you give one raze then you raze again just not together the creeps wont die,but if you raze quickly the 2 razes clear the mellee creeps,could be a bug two.