Not a hero idea, but something players can do to augment the lanes, special creeps, and affect the map environment.

[roocat81]

Creep and lane upgrades
Players can donate X amount souls / get something from the map / do X to unlock this / to augment the creeps for each lane
ether a temporary or permanent buff and visual upgrade look.

Donations go into a Bank that will accumulate souls and will trigger once it reaches a soul amount.
Give creeps better weapons or armour, make em bigger with more health or spawn a new types of creeps.

OR

This could be a form of artefacts you capture from defeating a mini-boss and bringing it back to base. Even when secured the opposition can invade the base and steal it. They Are Not locked out of their skills while carrying the artefact but they cant use the lanes to quickly escape.

Or maybe a type of new hero that causes creeps to be buffed and upgraded like the engineer in "Monday Night Combat" IDK

Donations or artefacts could Spawn assassin creep (werewolf or some SCP thing) that will stealthily hunt players randomly and only strike when they are half-health and on their own. Making going out on your own farming or fleeing without anyone else a little bit more dangerous. players can still shoot them if they spot the shimmer they give off but will flee rather than fight and stalker another player instead.

Activated Environmental hazards/debuffs
Such as ghost car/train traffic (like in Team Fortress 2) that can cause, not death, but push players into the air and away.
spirit people flooding the streets in rush hour that will slow down creeps and players unless they travel from rooftop to rooftop.

There could be a new map that takes place in a bayou swamp and swamp monsters/things spawn out to harass creeps and players depending on player level in lanes at a certain time and if the guardians and walkers are destroyed.

 

[NitramiuZ]

I like the idea.
I really like how people actually care for the urn now and such, having other objective too could be cool, and I like the idea of prioritizing a lane to put the upgrade on.

 

[roocat81]

Yeah, I liked the idea of carrying the urn objective to help your team. I think there should be more map objectives that help your team in certain ways.

But, its not told to the players it does something at the start, that should be found when you discover the objective.
sort of rewarding the player for exploring the map.

Right until game guides start telling everyone where it is and what it does haha

 

[TokenNoob]

I do think there needs to be one more other objective beyond the towers, midboss, and urn. I personally enjoy the dragon buffs from league. I think it'd be cool if the devs added a team stat buff objective on the map, except, unlike the dragons from league, the objective actively moves across the map, like a creature that needs to be hunted. The creature moves according to the state of the waves on the map, pathing its way towards where the trooper waves will meet and fight. That way it doesn't inherently give an advantage to one team over the other. The objective might even alternate between leaping over the rooftops or running through the tunnels. You can have different colour......"cryptids" (idk)....for different team stat buffs.

Also, I do like the idea of putting train tracks and a train on the map. There's already a trench-like impression that runs through the centre of the map. I reckon you could put train tracks there connecting the urn to the opposite altar, running under the lanes and around the midboss hall. It would add a level of danger to the urn run, although you could just get off the tracks but you have to be a little more mindful about the train when you do collect or place the urn down. Also think about the potential teamfights around those tracks

Just a couple of ideas, your honour

 

[columnatrajano]

this just made me think about neutral items in dota 2
making creeps give special items that go in a special slot would be easy enough