Fanon:Invasion (GellyPop)

Invasion is a concept gamemode for Diep.io, where players resides as a single team and must defend the 'Guard Base', located in the middle of the map (which mostly occupies the land of Pentagon Nest) from the evil tanks and polygons, which are all hostile to Guard Turrets and the players.

Gameplay
All players are on blue team, and all are already Level 45. The base is found in middle, which is actually the Pentagon Nest. However, most of its part is replaced by the Guard Base, which is where the team resides. There are four Guard Turrets located on the corners of Guard Base. These turrets had higher health than Dominators, and are required to be staying alive until the game ends for the players to win. Not all the turrets must be staying alive; even only one was left, victory can still be on the players' side. Defending them is a must, as they can only heal after not being hit for over a minute, compared to 30-second cooldown before regen of most other tanks. They can also be controlled, much like the Dominators, by pressing H once.

Once there was at least 5 players on the server, there will be a notification saying:"'The evil army of tanks and polygons are now attacking!'"As this shows up, Evil Polygons start spawning on the boundary of the map. Evil Polygons can be any polygons in the game except Crashers, Alpha Pentagon and Green Polygons, and they have a dark red color. Unlike most polygons, they are totally hostile (much like Crashers), and they will rush towards either the players or one of the Guard Turrets, dealing damage through contact. They also had higher health and body damage compared to Normal Polygons, and these stats increase as the game goes on.

Other than that, there is a small chance that an Evil Polygon would be replaced by an Evil Tank. These tanks are much like the playable tanks with their level also on 45, except that all their stats are slightly increased, making them much stronger. Any playable tanks, either Tier 4 or even Tier 1, can spawn as Evil Tanks, and mostly had an AI of an Arena Closer (moving towards target while shooting). Each Evil Tank has a random build, which sometimes doesn't match on themselves. For instance, an Evil Ranger with a rammer-build would show up. However, an Evil Smasher would never have a glass cannon-build, as bullet stats don't exist on it, and only the available stats would be given points for its build. As with the Evil Polygons, Evil Tanks also gets stronger as the game goes on.

There is also a chance that a Boss will spawn in the game. However, their health is drastically decreased, making them much easier to be killed so that their won't become the cause of the players' defeat. They also don't get stronger over time.

Players can still explore the map, but they will encounter no Normal or Green Polygons, nor the Pentagon Nest itself. Also, when the players die during the game, they can still respawn as normal, appearing on the Guard Base. Players who connects to a server with an ongoing Invasion game can still join and help defend the Base.

If one of the Guard Turrets was destroyed, a notification will appear:"'The [location] Guard Turret is now destroyed!'"When the players manage to survive with at least a single Guard Turret still standing for an hour (after the onslaught), there is a chance (1%) that the game makes the players victory every second, with each next second increasing the chance by 1%. When the game does it, a notification of winning will appear:"'YOU SURVIVED THE EVIL ONSLAUGHT! YOU WON!'"However, if the players failed and all the Guard Turrets are destroyed, this notification of failure will appear instead:"'YOU WAS OVERWHELMED IN THE EVIL ONSLAUGHT. YOU LOSE.'"When any of these events occurred, Evil Polygons and Tanks will stop spawning, and the map will be closed. After that, the Arena Closers will come, sweeping the map clean of any entities, including players, Guard Turrets, Evil Polygons and Tanks. The server will then restarts, allowing a new game of Invasion.

Trivia

 * It is one of the gamemodes where no Normal Polygons would spawn in any location of the map.
 * Invasion is mostly inspired by games where players must hold out an area and survive waves of enemies.
 * Evil Tanks can be played on Sandbox, but only the basic Tank one is usable. They are much stronger than normal tanks, as in the game mode.

Poll
What do you think of this gamemode concept? Challenging, but I like it. Challenging, and must be reworked... "Too Unfair!" - Spawnkilled Players Boring... IS THIS A JOKE?! Meh...
 * weird reaction, unable to be identified.