The Overmind by Slombeeper

Level 1:

-Swarm: All Zerg does 50% increased damage to heroes

-Hardened Carapace: Infested marines gain 30 armor and grants nearby allies 10 physical armor.

-Wreckers: Zerg Rush Zerglings deal 50% more damage against structures and take 50% less damage from minions and mercenaries.

Level 4:

-Infestator: Reduce the mana cost of Infest by 10. Quest: Each time you kill an enemy with Infest, increase its damage by 2,5%. Heroes killed increases the bonus damage by 10%. Reward: After increasing the damage by 50%, infest affects all enemies in an area.

-Psychic Reach: Increase the sight range of Cerebrate by 20%.

-Advanced Mutation: Zerg automatically regenerate health rapidly after not taking damage for 3 seconds.

-Metabolic Boost: Quest: Kill 100 minions with Zerg Rush. Reward: Activate to increase Zerg's move and attack speed by 30% for 4 seconds. 60 seconds cooldown.

Level 7:

-Psychic boost: If an enemy dies while under the effects of Infest, gain 15% more death experience and restore 60 mana.

-Antennae: Overlords sees 30% further, its cooldown is reduced by 10 seconds and it can see enemies hiding in bushes or vents.

-Survival Strain: Zerg heal for 20% of the damage dealt and they takes 20% less damage from monsters and structures.

Level 10:

-Chrysalis: Improve an ally hero. Improve range and Infest.

-Eternal Swarm: Summon a Zerg swarm. Control allied minions.

Level 13:

-Ventral Sacs: Overlords can be loaded with up to 6 Zerg units. While an Overlord carries these Zerg, their durations are paused. Press Overlord and use the "Unload" ability to release the Zerg at target location. If the Overlord dies, all units inside are killed aswell. Additionally, Overlords last for 20 seconds longer.

-Hunger: Reduce the cooldown of Zerg Rush by 2 seconds.

-Plauge: Infest slows enemies movement and attack speed by 20% for 4 seconds.

-Detector: Overlord reveals enemies in its sight radius for 4 seconds and has 20% additional health.

Level 16:

-Servants: While at least 2 Cerebrates are alive and on the enemy's side of the map, the cooldown of removing Cerebrates is reduced by 10 seconds and you regenerate mana 25% quicker.

-Communicators: While Zerg are controlled by a Cerebrate their attack and movement speed is increased by 10%. Zerg will now also follow your latest command given to them if they run out of Cerebrate's range.

-The Great Master: Increase the range of the core's attack by 40% and your mana regeneration by 15%.

Level 20:

-Part of the Swarm: Chrysalis effects lasts 6 seconds longer and its mana cost is reduced by 40 but grants no movement boost.

-Enduring: Eternal Swarm can now hold two charges and the Zerg last 10 seconds longer.

-Fury: Increase the health and damage of your team's minions by 10%.

-Unstable DNA: Channeling to remove Cerebrates is 100% quicker and refunds 30 mana. Cerebrates deal 245 (+4% per level) damage to enemies close to it when they die or are removed.

This is to summarize your Zerg units and their move speed. The base percent is their untalented normal speed and within brackets are all talents combined that give speed boosts;

-Zerglings: 110% (Max speed: 120% + 30% Activate)
-Overlord: 70% (Max speed: 100% + 30% Activate)
-Infested Marine: 100% (Max speed: 110% + 30% Activate)
-Minions: 100% (Max speed: 110%)

-Zerglings can be controlled if within Cerebrate or Overlord range.
-Overlords can be controlled from anywhere. (only Overlords can gather experience)
-Infested Marine and Minions can only be controlled if within Cerebrate range. (Minions can only be controlled for 10 seconds when you pick Eternal Swarm, then they are regular minions again.)

How does Central Mind work on maps like hanamura where the core is protected?
-I made sure to think of that. When you shoot the payload on the core it will be damaged, this increases your team's XP generation, giving levels quicker. But you will not benefit from the extra damage and splash from the core. It's the opposite om maps like cursed hollow because you will not get that bonus XP generation until the later game but you will benefit from the damage and splash since your enemies must directly attack the core!

How do you earn experience? Soaking?
-You can only gather experience from Overlords. This is to prevent constant soaking with cerebrates in all lanes. By sacrificing your Overlords you have to be careful with your placements so that your enemy won't kill of your Overlords and increase the cooldown of your Zerg Rush ability. This is the reason why the cooldown is so high. Risky but rewarding.

It doesn't seem like the Overmind does much. Too weak, too good?
-I think that the player that plays the Overmind has to put a lot of attention to multiple things, positioning of cerebrates, overlords and summoning zerglings. Additionally they need to keep using their abilities efficiently to save mana and use infest during teamfights to summon that infested marine. At level 10 the Overmind will get a big buff to his kit, either increasing his strategic overall power with Infest and Cerebrates or gaining the control over his team's minions and becomming a scary seiger. At this point the Overmind will have to micro-manage and keep an eye on cerebrate placements and use the remove ability to save the cerebrate before an enemy finds it because the Overmind can be more aggressive as it is more rewarding.

Remember that this is made just for fun. I'm not a developer. I have tried making it balanced. But feedback is appreciated, thanks.

Why does the Overmind use mana?
-Short answer: limit his power so that pros can't constantly spawn Zerg everywhere and at any time. It may seem that the Overmind lacks mana but that's not true. I made a quick program and tested the mana cost against its regeneration. The results: you can quickly build back your mana, so you won't be constantly around 20% mana. But using all of your abilities immediately when off cooldown drains mana fast. This adds a bit of restriction and management into playing the Overmind :)

Mercenaries
So on braxis holdout you free the mercenaries from being Infested when you capture them. Imagine if you hade the Overmind on your team and the mercenaries became Infested when you capture them instead! This could work on all types of mercenaries/bosses on any map!


Announcer
The Overmind could also give encouragement or quotes to your team or trigger dialouge when an enemy dies or when a fort falls. This is to create that "feel" that the Overmind is there and is participating.

Unit durations
Zerg units' durations are hard to notice when you have a lot of Zerg. So I suggest that the duration timer tab below their health bar is thicker. Just to make it easier to see.