The Old Gods by Slombeeper

A unique Assassin with great area denial and disruption from range.

Lore:
Many horrific manifestations have been created by the Void Lords with a single goal: to consume all of existance and turn it into a realm of eternal torment. By chance, the Void Lords infected the world of Azeroth with the four Old Gods C'Thun, N'Zoth, Y'Shaarj and Yogg-Saron. When the titans realized that the world-soul of Azeroth was in danger they sought to fight off the monstrosities' endless armies and stop their corruption, but with little luck. Eventually they titans themselves tried to tear the Old God Y'Shaarj from the surface itself which caused collosal damage to the world. This caused the realization that the only way to stop the Old Gods was to imprison them and stop their corruption. But no prison holds forever... Such power is inevitably drawn into the Nexus. With a new realm to devour, the Old Gods have now arrived, driving powerful Heroes mad.
.

Abilities and role:
The Old Gods would be a Ranged Assassin, a hybrid between Sgt. Hammer and Abathur, who can at the start of the game alter between an Old God to play as with a talent choice. Each Old God talent was designed with their own characteristics in mind and a unique quest to raise their own power. Using their specific power, the chosen Old God can aid your team to victory.

Their main ability is their Maddening Whispers (E) which is weak at first but can over time become very scary and dangerous. It ties well into lore and fits their theme perfectly as they drive people insane and cause them to break down. Roughly 3 enemy heroes can be kept at 5 stacks at all times which means they are slowed and take MUCH more damage from you, though this is difficult because the enemies might not be visible for you to affect them. This keeps them from being too overpowered against all enemies, so they have to focus on a single enemy to break down which makes it easier to counter and less frustrating to play against. While playing as the Old Gods, the player will have to focus primarily on tanks which are harder to kill since they will be alive for longer and building up a lot of stacks can greatly empower yourself to contribute in a teamfight.

Void Blast is their main source of utility but also damage. It is a skillshot and requires some aiming to land with a relatively small hitbox but is very rewarding if it hits, dealing damage and rooting enemies around the target. It deals less damage to minions because of this so that it doesn't instantly clear waves. Use this ability to support your team or deal poke damage if needed. It is especially useful when teams are together because it can hit many enemies.

Crusher Tentacle is the Old Gods' main teamfighting "prescence" as they will act as both damage and body blocking. Tentacles have very low health and dies in about 2 basic attacks. It requires clever usage of the charges it hold to efficiently use them and not waste all charges at once. Use this is their primary source for damage and area denial. One could think of them as a Napalm Strike but more damaging.

Servant is the first heroic ability which causes an enemy with 5 stacks of Whispers to fall under your control for a short duration. This is a great support tool for both removing a Hero from the enemy team and adding more direct combat power for your team. To compensate for this upside, the ability is restricted to heroes with stacks, has a slow cooldown and requires a short channel. This ability would be best used on high damaging heroes that can punish their nearby allies.

Hour of Twilight is a more strategic heroic that enables the Old God to extend their ability range or for area denial. The Old God can make use of reduced cooldowns to unleash a lot of abilities and Whispers to cause chaos among the enemy team and deal a lot of damage if they fight near you. Visually, the Old God would become transparent if a hero would be behind it.

If the Old Gods die, their trait is activated, enabling them to use Maddening Whispers to keep stacks on Heroes from the grave (or from the Void because the Old Gods don't die). The Old God player should utilize the trait as much as possible to keep dealing big damage to enemies.