Role of Lifestealer

You can still go racecar with him and be perfectly fine. Not good, but fine. Or Blink Dagger + Orchid Malevolence. Control is really good for that purpose.

for the heathens who don't know what the racecar build is : Phase Boots > Drum of Endurance > Sange and Yasha.

i prefer phase into s&y into mjollnir into basher.

Since its mana-free casting update, I've seen Blink Dagger used quite often to alleviate most of Lifestealer's "yarn in the wind" syndrome.

I generally think Drum of Endurance, although pushing you to that 500 movement speed mark, is overkill and the 481 movement speed you get without it, is enough. It costs 1875 gold (if I recall) and for that money you can almost purchase a Hand of Midas which will help you stay ahead of the curve in terms of exp, and gain you a lot of surplus gold by 40 minutes. In addition, because you're missing out on Power Treads, the Hand of Midas gives you the +30 Attack Speed to make up for it.

Phase Boots
Hand of Midas
Sange and Yasha

Is a great base core, and usually what I aim for each time.

The reason why he became a mid game carry are the nerfs that he received.

Lifestealer has a very serious jungler potential, but due to his escape skill also can push lanes, but generally players do not push lane with him.

https://www.dotahq.com/dota2/heroes/Lifestealer/54