Motif: Compression
Apprentice - Ebonblooded.
Cosmetically, Arkash's blood darkens to an unnatural dark maroon shade, which in turn further darkens his scales, skin, lips, mouth, and tongue by extension. This makes it easier for him to blend in with the dark, but can also alert those who look upon him in the harsh sunlight that something is amiss, especially in his humanoid form which reflects a slight purple undertone for his skin. In lamp or candlelight, the change is a lot more difficult to recognize as the lighting is softer.
Journeyman - Pressed Edges.
The ability 'Suffuse' takes a lean toward the 'Sharp blood' property, especially with any abilities oriented around hardened or shaped blood. The edges Arkash can produce are a lot finer and sharper than they would otherwise be, but at the cost of draining the potency of the other suffuse-able properties. 'Acidic Blood' is only slightly weaker, 'Combustible Blood' is about half as potent, 'Unstable Blood' is severely weakened, and 'Diseased' is almost nonexistent in terms of potency. Altogether, the redirected focus of strength and potency makes Arkash's Suffuse more than thrice as sharp.
Expert - Loaded Veins.
The blood in Arkash's veins doubles in density - This is the entirety of the mutation, but the change carries a lot of implications and adverse effects both negative and positive. The most notable change is the weight of his body, which will increase by ten percent. This isn't all that significant, especially as Arkash will grow conditioned to the additional weight with time, but it does pose unique challenges in the fact that he's more prone to blood clots. Becoming sedentary increases the risk of blood clots along with poor hydration. In fact, Arkash will not be able to go more than a day without water whereas most other races can last three times as long without. If he forgoes hydration, he's likely to experience heart attacks and death. Additionally, he's slower to recover from blood loss, which can hinder his blood magic abilities. In his human form, he's prone to overheating and heatstroke.
This mutation isn't without its boons, however, as Arkash becomes significantly more resistant to diseases and illnesses: the microorganisms are smothered in his veins. Additionally, he requires a greater dose of medicine and poison alike to take effect. On more passive levels, his wounds coagulate much quicker and his stamina improves greatly with the bounty of oxygen in his blood vessels. His body retains heat easier, which is a blessing in his True and Faunis forms but hinders his humanoid form. Because of the increased potency of his blood, he is able to bleed more without suffering negative effects as quickly; he has a greater threshold for exsanguinating. Additionally, all abilities shaped with his own blood are a lot more potent, excluding Sacrifice.
Master 1 - Singularity.
Arkash's Bloodfury is mutated to provide him a significant means of defending himself at the cost of nearly all its offensive ability. Upon the release of his lifeblood in Bloodfury, the explosive wave of destruction that rips outward and would otherwise decimate the opponents that surround him only continues for a radius of two feet, stops, then retracts to his body. The blood then covers his form in random patches with various levels of thickness that ultimately depend on his position at the time of release, the amount of blood he has left to release, and obstacles in his environment. It will attempt to spatter and wrap his limbs, head, tail and body with no clear coordination, and can wrap his joints, eyes, nose and even his mouth shut before it hardens with impressive toughness and durability (though this can be undone with Sway). It should be noted that the burst of blood is still lethal within the two feet that it travels and can easily inflict the full damage of Bloodfury point-blank.
Upon releasing the blood required to form his casing, Arkash will be overcome with incredible fatigue and disorientation, shock, and even loss of consciousness; he will experience symptoms of blood loss at varying degrees depending on how much he has lost beforehand, how much was expelled to create his casing, and how physically exhausted he was prior to casting Bloodfury. Such symptoms often recede within a minute of casting, but can take longer depending on how much was spent.
Master 2 - Contract.
Arkash's Blood Magic abilities have half as much range due to the compression of all blood he manipulates. In order to produce ranges similar to Blood Mages without this mutation, Arkash needs to use twice as much blood, as all the matter is compressed to double in strength and weight. For example, in order to fashion a dagger with Bloodshaping, Arkash would require twice as much blood as he otherwise would, but the dagger would be twice as heavy and twice as strong/durable as a regular blood-shaped dagger. Hemorrhage, Living Bomb, Bile Construct, Blood Torrent, and Puppeteer all require twice as much blood to perform. All bar the last operate at greater potency/force because of this.
Because puppeteer requires two liters of blood to perform with this mutation, the target will be very near exsanguination by the time Arkash manages to take control of their body. For that reason, the body will naturally be a lot weaker by the time Arkash can assume control - The ability is almost completely redundant due to this increased cost. It should be noted that the blood he shapes with this mutation active is darkened considerably when it's compressed, and is a lot harder to recognize as blood.
Image source.