Necrophos

Rotund'jere the Necrolyte is an item-dependent caster Hero who typically plays as a midgame carry. His skills are most effective in team fights where he can damage enemies and heal allies simultaneously, while picking off key enemy heroes with his ultimate. Necrolyte is most dangerous when his enemy is severely injured, instantly killing them with his ultimate while recovering his Mana after killing his foe. Wherever Necrolyte walks, death comes slowly but surely.

Necrolyte is naturally fragile, he's not a strong physical attacker, and his abilities require him to stay in the middle of fights. Ideally, by casting Death Pulse repeatedly and staying alive long enough for enemies to start dropping below half health, Necrolyte can quickly decide the fight in his team's favor with his Ultimate. To accomplish this, Necrolyte requires health and mana boosting items to keep himself alive and threatening. It is usually not recommended to play Necrolyte as a support hero, as he benefits greatly from gold and experience. Necrolyte is recommended for intermediate to advanced players.

Tips

 * Taking one point in Heartstopper Aura in the early game allows for harassment of enemy heroes by means of simply standing near them, as you would in early-game laning.
 * Note however that the aura affects enemy creeps, and thus taking it will push the lane. Should you lane with a farm-dependent carry, it is unwise to push as it complicates or simply removes their creep farm.
 * If one is new to Necrolyte and unsure about Reaper's Scythe, it will almost definitely kill targets at about (or lower than) 35% hp (with sceptre it's generally any amount under 45%). The damage calculator indicates that about 45% is a safe kill (with sceptre anything under about 55%), but this does not factor in Magic Resistance.
 * Note that should an ally kill the target in the brief delay between the stun and the scythe, the kill will be theirs.
 * The philosophy behind Reaper's Scythe is that (owing to Sadism) it will return its mana expenditure, having been used for a sure kill. However, there are emergencies in which it could be used simply for its stun; such as interrupting Pudge's or Enigma's ultimates or preventing the escape of an enemy hero who must be shut down.
 * Necrolyte can very easily be built as a tank and in most circumstances should be; you may gear for Strength (he does not need excessive Intelligence as his autoattack is not useful and his spells are not particularly expensive) and consider a Vanguard instead of or in addition to your Mekansm. The reason he is usually built as a tank is because he needs to stay alive in violent encounters to heal his allies (a good enemy team will focus him first), and also because the longer he is alive for, the more damage his aura will do and the better chance he has of landing a crucial Reaper's Scythe.
 * Necrolyte is quite an effective counter for invisible heroes as if they stall before they attack his aura will whittle down their hp, and his Reaper's Scythe will prevent them escaping via invisibility before they die. He is also very good against heroes with abilities that deplete their own hp, such as Pudge and Huskar, but in order to withstand their assault he must usually be built as a tank.
 * A Dagon can prove effective; providing Necro with more intelligence as well as a means to combat his crucial lack of burst damage. Using it on an enemy will edge them closer towards the last segment of their hp (circa 30%) at which point Reaper's Scythe will kill them if used. However, upgrading it fully is not advisable; as he benefits more from other items.
 * Aghanim's Scepter can be purchased on Necrolyte and will increase the damage ratio to 1.2, this means that Reaper's Scythe will deal even more damage to more durable heroes. To calculate the damage of Reaper's Scythe, multiply the missing health of an enemy. For example, if Axe has a maximum health of 3,900 and he has lost 2,200 health, multiply 2,200 by 1.2 and the damage of Reaper's Scythe will be 2640, (ignoring magic resistance), which is more than lethal enough to kill him.
 * Necromancer's role is notoriously debated; as while his abilities appear supportive his Reaper's Scythe generally secures kills only for himself, and atypically of a notional support unit he benefits hugely from gold and leveling. The duplicity of his carry/support role stems from his unique stance in encounters; which is largely supportive until an enemy becomes weak, at which point he will kill them himself; and because of the black-and-white mechanics of his abilities this role cannot be variated very much. He is best viewed as a potentially very dangerous support unit.
 * Necrolyte is countered by any hero with high HP regeneration, such as Dragon Knight and Quas-focused Invoker; owing to his modus vivendi being to wait for his aura and continual Death Pulses to gradually reduce enemy HP to a stage where his Reaper's Scythe can kill them.

Trivia

 * Necrolyte's Alternate/Fun name was "A Phoe Gyi", which means "an old man" in Myanmar language.