Why Play Lifestealer?
Lifestealer is a very simple hero, a carry that sustains themselves from hitting the enemy. Lifestealer is capable of slowly whittling down the enemy, brushing off enemy spells, and hiding inside his allies until the right time to strike.

Stylistically similar to Bloodseeker, Lifestealer specializes in hitting fast and chasing down fleeing foes (Ghoul Frenzy), and naturally heals from fighting (Feast). He can become immune to spells (Rage) which can make him an absolute menace to fight for spellcasters. His ultimate (Infest) allows him to completely hide inside an ally and burst out in a bloody shower, one of the few legitimate ways you can jumpscare someone in Dota.

He has two passives, which means he doesn't need to press many buttons. Simple to learn, but good execution makes the difference.