Arstais

Arstais is an Elder Dragon first introduced in Monster Hunter: Echoing Roars. It is the flagship of said game, and acts as an antagonistic force in it.

Physiology
It's body is similar in shape to a Fatalis, however it is noticeably smaller. But still larger than most other large monsters. It's body is covered in dark green spine-like scales and seems to have black claws. It's arms are somewhat bulkier and the hands are made for striking opponents and are covered in much more hard and spiny orange colored scales. It's fists have one blade-like spine on the middle finger's knuckle and around it's wrist is a weirder spine that seems to be leaking some sort of gas that illuminates around it. The tips of the fists have bone-like purple structures that seem to be very reflective, or have something inside them. it has large wings with dark purple webbing and red markings on them. It's tail is alot shorter than a Fatalis', however it is equipped with some blunt spikes on the sides of the tail all the way. At the tip of the tail, it has three long spikes on both sides of the tail, similar to a Stegosaurus tail. It has a long serpentine neck like of a Fatalis, but it seems a bit more shorter in general. It's snout also is a bit more broader. It's head overall seems similar, but different enough. The top of it's head and back of it's head seem to be covered in these green scales, but it's face in general is more covered in the orange scales. It has horns made of the same purple structures and it's eyes glow yellow much like the illuminating "aura" it produces.

Behavior
Seems to be a cunning beast that will try and take advantage of tricks to gain what it wants. It is territorial however when something enters it's territory. Even when outside their territory, they are aggressive and always keep at the fight, rarely fleeing if it needs to flee.

An Elder Dragon of high power. They are quite difficult to find due to their nesting habits and how they tend to roam alot. Their ecology is still being studied.

Habitat Range
Commonly found nesting in deep caverns, but sometimes in abandoned forts or castles. They however roam where ever they please.

Ecological Niche
They are beyond the throne of the food chain, and sit outside of any natural food chain. They consider many monsters and challengers a meal. However they do have To compete with monsters such as Fatalis, Alatreon and Shantien. Their preferred meal are monsters that use the Dragon element, but they have to be careful not to take too many injuries as they are weak to Dragon in a way.

Biological Adaptations
Arstais are brawlers. Despite being some of the smallest high level Elders, they are able to give a heavy wallop. Their arms have power and toughness to them, similar to Rajang arms. However, it can infuse them with the Dragon element or it's aura for more effect. It is unknown what this aura is, but it seems to be some form of gas. It can capture Dragon elemental energy inside themselves, and it makes the beast more powerful. Any other lifeform that gets hit by this gas suffer from a weakened body. It's tail, while shorter, is alot more muscly which allows the Arstais to use it more effectively for combat. However, they cannot walk on all fours, so the closest they can do is run similar to a theropod dinosaur. Even then, their powerful legs, wings and tail keep them from tripping.

Moves and other states
Arstais tends to be somewhat quick with it's own slow moves, but since it isn't in any traditional MH game (for now), it fights much like a fighting game boss. It cannot be Frenzied, but it can be Tempered and even become Arch Tempered.

Arstais has alot of moves in Echoing Roars, so here's some that you should keep mind of especially. When enraged, Arstais will gain the Dragon element in most of it's attacks, and most of it's attacks (especially the gas ones) start inflicting Suppression. It will also start this state with a Break Roar.
 * Combat Fist, the user performs a powerful punch that boosts the user's attack if it hits. This does not buff the user if the attack is successfully blocked.
 * Hammer Fist, the user performs a slow starting yet almighty slam attack, has a 100 % chance of inflicting Stun and breaks blocks and counters. The user can slowly move and turn before the move is excecuted.
 * Breath, the user is able to breathe out Dragon elemental energy and it's unusual gas. Getting hit by the gas inflicts Defense and Resistance down.
 * Concealing Energy, a command grab. The user conceals the target with the gasses, and chucks them away, causing an explosion of the gas as well. Inflicts Defense and Resistance down, but can also inflict Suppression.
 * Break Roar, the user does a special roar that if the target is in it for too long, will get affected with Technique Broken.
 * Aura Armor, the user conceals their body with their own aura. Arstais' aura will weaken the target's elemental attacks that it recieves. Being near it for more than 45 seconds will inflict Defense and Resistance Down.

Arstais is a heavy monster, meaning they are very hard to launch. It does not help that it is capapable of flight to some extent in battle. The best way with dealing with this monster is to depleting it's HP to 0.