Mannoroth by varkarrus

Level 1:

Overwhelming Howl: Howl of Terror pushes enemies back, but does not stun or interrupt channeled abilities.

Dampen Magic: Every 8 seconds, gain a charge that reduces damage from the next ability that hits you by 50%. Stores up to 2 charges.

Burst of Speed: The movespeed from Devastation becomes 220% instead of 150% for the first 0.5 seconds

Consume: Dark Grasp heals you by 4% of your max HP for every minion struck by it, and picks up regeneration orbs.

Level 4:

Vampiric Feast: Auto-attacks heal you for 5% of damage dealt to all targets hit.

Warlord: Every basic attack you make against a hero reduces the CD of Howl of Terror by 4 seconds, triggering only once per attack.

Spur Onwards: Howl of Terror increases allied minion attack speed and movespeed by 100% for 2 seconds

Furthest Reaches: Dark Grasp has +50% increased range.

Level 7:

Focused Fissure: Every 20 seconds, your basic attack deals +50% damage to a hero, with doubled range, but it hits in a line instead of an arc. The CD is decreased by 1 second every time you hit someone with an auto attack.

Uprise: At the end of Devastation, or when you recast it, deal 133% damage to all nearby targets, and knock them into the air. Enemies that have already been hit by the charge will only take the 33% bonus damage.

Bellow: Howl of Terror has 20% increased range, and has half its mana cost refunded if it doesn't hit any heroes.

Pit Armor: Gain a charge for every minion and mercenary you kill. If you are hit by an enemy hero, use 10 charges to gain a shield for 20% of your max HP for 4 seconds. Store up to 15 charges.

Level 10:

Rain of Fire

Doom

Level 13:

Siege Breaker: If you collide with a structure while using Devastation, you deal 200% damage to all structures in a large AoE around the point of impact.

Castle Assault: Keeps do not slow you down, and you take 50% reduced damage from all structures.

Giant Crusher: Auto-attacks against enemy heroes deal 2.5% of their max HP as bonus damage.

Level 16:

Absolutely Unstoppable: Become completely unstoppable while using Devastation.

Oversized: Your collision box displaces units while you move, dealing no damage, and without interrupting channels.

Imposing Presence: Enemies that attack you have their attack speed reduced by 40%.

Crush Underfoot: Devastation instantly kills minions, but the CD is increased by 0.2 for every minion killed.

Level 20:

Burn: Rain of Fire's duration is extended by 2 seconds for every takedown that occurs within its area.

War Stomp: Doom Guards can use stomp every 8 seconds, dealing damage equal to their attack damage, and stunning nearby enemies for 1 second. Damage is doubled against minions.

Fury of the Lord: Attack in a cone with doubled auto-attack range, and +228 bonus damage, but only affecting minions and mercenaries. This ability triggers once every 10 seconds.

Bloody Rampage: Move at 80% movespeed while attacking. (64% default hero movespeed)