Tale of Diep:Umbra

This is just a concept idea for a new boss in diep.io. Such enemy doesn't exist. (Maybe) Umbra is not made of shadows, shadows are made of Umbra.

Overview
Umbra is a large Assasinator with various weapons and the ability to remain cloaked while moving. Even while firing it can still remain invisible, only revealing its body once getting shot.

Umbra has a rare chance of spawning in the arena. It will spawn in a remote area of the map, immediately cloaking and begins to move around with no set path. It will cease to fire any of its weapons while idle.

This boss is a very stealthy entity, it can often strike opponents without warning. Sometimes it can fire a single bullet from a distance. Other times it can remain in the same location and fires blast of bullets at point-blank range. Umbra can also create a cluster of mines that will explode upon getting too close.

Engaging a fight against Umbra will require extreme patience, acuity with timing, and awareness. A team can make the fight easier.

Umbra has two BGMs, one is while being cloaked, and the other is while visible. Currently the visible soundtrack is made.

BGM:



Design
Umbra is a light lavender enemy, in the shape of an Assasinator Crasher variant. Three barrels in a formation similar to a Spread Shot tank class is positioned on the front end of the two sides. A shot, heavy barrel on a trapezoid base is directly at the front. A Thorn Mine launcher is positioned on the very back internal side of the boss.

.

.

Boss Stats
Umbra has 6,500 HP, and an additional 12% reduction to enemy ammunition. It has a base regeneration of 12 HP per second, if left unharmed for over 45 seconds it will boost regeneration by 300%. Umbra will deal 28 HP of body damage per hit. Umbra moves twice as fast than the Guardian of the Pentagons. This boss will reward 65,000 EXP to anyone who dealt the last blow of this boss.

Front Barrel
Umbra's front sniper-like barrel will fire a fairly large, fast, and high penetration bullet that can pierce through bullet streams with ease. The bullet comes fast and hard, often fatal to tanks with low max HP. Lucky this cannon has a long reload time. Each bullet is near the equivalent to a maxed penetration, damage, and speed Assassin tank class bullet. It moves ~9 tiles per second.

Side Cannons
Along the sides of Umbra, six barrels are placed in a pattern similar to the Spread-shot tank class. Bullets fired are smaller and move slower than the front cannons. The firing pattern always start from the far back cannons first then firing up to the front cannon. Each cannon firing has a 0.4 second delay during its cycle. It then has a larger delay of 3 seconds before repeating. Umbra usually fires these cannons when it sneaks up to a larger group of tanks and then unleashes it at once.

Bullets have high penetration and medium damage, quite dangerous.

Thorn Mine Launcher
The Thorn Mine launcher on Umbra will rapidly produce small explosive traps with four thorns on each side, similar to those created by the Skewer Phage. The Launcher itself will not fire while Umbra is cloaked. These that Umbra produces have a slightly different appearance. It looks exactly like a Phage Mine but it is the same color of Umbra's body. They behave like traps in how it will loose momentum when fired and then stop in place.

If a tank (or another enemy) approach the mine, it will collapse into itself and explode, releasing four thorns in four directions and a small ring of 12 tiny slow bullets. When the mine explodes, the polygon body will destroy itself. The Thorn Mine created by Umbra has 120 HP and will not deal any body damage (as they would explode instead).

Thorns released by the mine will fly very fast. They will deal 3 HP of damage per 1/2 second for 5 seconds. This adds up to an additional 30 HP of damage dealt through one thorn. Upon being ejected from the explosion, it will gradually loose momentum. Upon stopping it will fade away. The small ring of bullets have the same color as the mine's body. These bullets have moderate penetration and move very slowly. They will deal 14 HP of damage per hit. The ring of bullets will not last very long, only for 3 seconds. Should the mine detonate nearby other mines will also cause them to explode, creating a deadly chain reaction.

Behavior
As soon as Umbra spawns, it immediately cloaks itself and wanders around in the Realm. When a tank is in range, it will be targeted from afar from Umbra.

Offensive
Umbra will first fire its front cannon at tanks as an attempt to scope down any ones unfortunate to fall victim. It will continue firing until a tank gets too close in range to its body, and thus it will cloak itself and begin to encircle the tanks. Occasionally it will suddenly get close to a tank and fire its side cannons to pepper tanks with damaging bullets. It continues to go through the cycle of appearing and disappearing as more and more thorn mines are produced to create a hazardous battle. Umbra can appear for a short second if shot, so tanks with spreading shots can reveal it more easily.

Occasionally Umbra will rarely do a "blitz" attack, where it fires its cannons a cycle of three times in a short moment, causing more chaos.

Defensive
Umbra is aware about itself loosing HP, thus it will cloak and run away as far as it possibly can from tanks, It usually does this when it approaches 700 HP. It will remain uncloaked for a second as it fires thorn mines behind to slow down tanks. Umbra will be in range of the tanks as it slowly fallows them while regenerating. Upon getting 3/4 of its max HP regenerated, it will continue its vicious cycle again...

Trivia

 * Originally was not going to be added, but eventually I convinced myself to create this boss.
 * Umbra is a name for the darkest point of a shadow, usually in terms of large celestial objects.