Obsidia: Best build, Counters

Return to Bone

Obsidia gains Bone Energy whenever she deals damage. Basic Attacks grant 1 Energy against non-hero units and 2 against hero units or Turrets. Skills grant Energy equal to 3 times the amount granted by Basic Attacks against the same unit type. No Energy is gained from hitting creeps.
When Bone Energy reaches 30, it forms a Bone Shard, up to 25 shards. When Obsidia uses Basic Attacks, all Bone Shards strike the target, each dealing (+6% Total Physical Attack) Physical Damage and inheriting 6% Attack Effects.
Killing an enemy hero directly grants 1 Bone Shard(s).
Obsidia's Basic Attacks deal 70 (+70% Total Physical Attack) Physical Damage, inheriting 100% Attack Effects.

Abyssal Bone Needle

CD: 4.5 Mana Cost: 35

Obsidia launches an Abyssal Bone Needle, dealing 325 (+80% Total Physical Attack) Physical Damage to enemies hit and triggering Return to Bone on the first enemy hero struck.

Phantom Shadowmeld

CD: 4.5 Mana Cost: 40

Obsidia descends into the Abyss and enters Shadowmeld Form, gaining 500% Movement Speed for 0.3s.

Hunt of Bone

CD: 40 Mana Cost: 100

Obsidia shoots Bones of Wrath in the target direction, dealing 125 (+60% Extra Physical Attack) Physical Damage and briefly stunning the first enemy hero hit before pulling herself to the target. The Bones of Wrath tethers Obsidia to the enemy, preventing her from moving more than 4 units away. While tethered, the enemy cannot use mobility skills, and their movement drags Obsidia along. Obsidia also gains 5 temporary Bone Shards stacks and a shield equal to 200 (+ 25 per Bone Shard stack). This effect lasts 3s.
While tethered, Obsidia can move through obstacles and use Basic Attacks while moving. Phantom Shadowmeld is also enhanced: its duration increases to 1s, and its cooldown is reduced to 33%.