safe and imo best build: (bottle+wand) pt bkb manta b.fly HotD
fun items lothar and dagger
more fun items travel janggo yasha euls dagger force staff full mobility:)
DK :
tankiness build : PT , BKB , AC , HoT , Pipe , Sange And Yasha
carry build : BoT , Radiance , Vanguard (built only on a certain situation) , Buriza , AC , Satanic
SF : BoT , Blink Dagger / Lothar , BKB , EoS , Butterfly , Desolator
it all depends on the game ... there are some games u dont even have to get bkb .If ur farm is good enough early on rush manta.Assult is pretty sweet on shadow fiend Blink is a waste of money for me if you want to win unless u are raping them hard early on and u want to keep on farming enemy heroes.
Item choices:Fly/SKadi/Mkb/Daedalus/Ethereal blade/Linken/Bot/Any orb effect(unique attack modifier)
Veil works pretty sweet on shadow fiend as well but I suggest some sup ally getting it.