Grom Hellscream is in a constant battle to sate the demonic bloodlust within his veins.
Instead of Mana, Grom manages a spectrum that ranges from 25
Sated on one end and 25
Bloodlust on the other. He begins each match at 0, directly in the middle.
As Grom gains
Sated, he gains Armor and Cooldown speed, up to 10 Armor and 2x speed.
As Grom gains
Bloodlust, he loses Armor but gains Basic Attack Damage, up to -10 Armor and 25% additional damage. At full
Bloodlust, Grom also gains 20% increased Attack Speed.
Grom gains 2
Bloodlust for every basic attack against non-structure enemies, doubled against Heroes.
Grom gains 4
Sated for every enemy killed, doubled against Heroes.
Since he can reach both 25 Sated and 25 Bloodlust, I do not see why his passive should affect his Armor. Sure, it fits thematically, but it makes it difficult to calculate damage as and against him, and it also conflicts with [Warlord of Chaos]. If you still want to keep Armor, he can gain 10 Armor while fully Sated. Something like this:
>Killing an enemy grants 4 Sated, doubled from Heroes. Each point of Sated causes Ability cooldowns to recharge 4% faster. While at full Sated, gain 10 Armor.
Basic Attacks against non-Structures grant 2 Bloodlust, doubled from Heroes. Each point of Bloodlust increases Attack Damage by 1%. While at full Bloodlust, gain 20% bonus Attack Speed.
How fast does he move during [Sundering Leap]? Is it as fast as Varian's [Colossus Smash]? Speaking of Colossus Smash, is this leap not just its weaker version?
[Gorehowl Sweep] is incredibly weak. Leoric's [Skeletal Swing] has almost triple the range and quadruple the damage, but also Slows targets. I suggest increasing its range to 4 and damage to 120.
[Giant's Heart] heals you, not increases your maximum Health, right?
Why does [Hell's Scream] have two different cooldowns? It also looks like it turns Bloodlust into Sated, but at what speed?
Either way, I think it being a 3 second channel is incredibly clunky. I suggest reworking it like this:
>After 1 second, vent out all of your Bloodlust in a demonic scream, becoming fully Sated and causing enemies around you to lose 10 Armor and 30% Movement Speed for 3 seconds.
[Warlord of Chaos] does not feel like an ult. Unless gaining Sated causes you to lose Bloodlust and vice versa, which is not mentioned anywhere, this effect can easily be an active ability talent.