Hero Mastery

Nyx Assassin

A subterranean assassin: Vendetta gives an invisible burst, Impale stuns a line, Mind Flare punishes big mana pools, and Spiked Carapace reflects a stun back at the attacker.

Mastery parameters

Your XP and damage per game against other Nyx Assassin players — average vs Top 20%. Supports are not graded on GPM.

Members only

Learning journey

1 Know the kit
2 Win the lane
3 Timing & rotations
4 Win the fights
5 Master

5 stages, each with one target from your own games and one short quiz. Make Nyx Assassin your mastery hero to start — progress shows on Home and Arcana.

Phase by phase

Laning: zone their carry with your offlaner

You 40%Team 60%

Skills in lane — Pro supports max Impale (Q) first — 87% of 376 games since patch 7.41, then Spiked Carapace (E). First talent at level 11.
Vendetta pickoff — Vendetta in unseen, Impale to lock, big burst — delete an unaware enemy support/mid.

Skills 1–7

Starting items

Iron Branch17%
Tango17%
Blood Grenade15%
Sentry Ward11%
Boots of Speed9%
Faerie Fire9%

Pros buy this phase

Tranquil Boots69%
Arcane Boots28%
Power Treads3%

The Soft Support's job this phase

Stand between the enemy carry and the creeps — make them choose between XP and HP.
Secure the minute-6 power rune for your mid — that's your first rotation.
Place Observers on rune spots or enemy rotation paths, not random cliffs.

Counters & weaknesses

Invisible hero

The items that shut Nyx Assassin down, 3 heroes that trouble it, and your answer when you play it.

Members only

Why this way? How OpenAI Five learned

One hero, one role first
OpenAI's first bot played only Shadow Fiend, only mid, until it mastered it. Stay on Nyx Assassin in one role before moving on.
Small, measurable rewards
OpenAI Five was rewarded for last hits and staying alive long before it understood winning. That's why each journey stage has one number to hit.
From yourself to the team
Its 'team spirit' rose over the game: early on, look after yourself; late, play for the team. Each phase's meter shows the split.
Use proven builds
OpenAI Five's builds were hand-written, not trial and error. Start from the pro build, then experiment.

Phase items: what pros buy on this hero (OpenDota). Parameters: percentiles of players on this hero (OpenDota). Item effects checked against Valve's own item data.