Cobalt is actually DBY the yoshi changed into an Istrala. As such, Cobalt generally has the same personality as when he was a yoshi. While a yoshi, something happened that literally tore his negativity and his conscience from his being, each forming their own embodiment. This left him in a limbo state, having no conscience to tell him right from wrong nor anger or jealousy to compel him to do wrong. Despite everything, he has an amazing sense of humor and loves to laugh and joke around. Cobalt has more of a sense of doing what is right from the enyo he merged with.

While still a yoshi, DBY was out taking a walk through the forest. He wasn't adventuring nor exploring, just simply enjoying a walk through nature. During this nature hike, he had come across a small creature that resembled a small imp of some kind. It really was unlike anything the yoshi had seen before. He was highly curious about the creature, and thought it was kind of cute. The creature seemed harmless enough, and oddly, looked as if it was just as curious about the yoshi. Perhaps neither being had encountered the other species before. It seemed their mutual curiosity lead them both to be willing to take the risk of trusting the other, and soon enough the two were playing games, sharing lunch, and exploring the forest together. The imp-like creature would even perch upon the yoshi's shoulder. DBY would talk to it and it seemed to understand what he said, though the yoshi was clueless what it may have been attempting to say. Still, he felt a special bond with the creature. When it was time to head home, he smiled and gave the creature what was a goodbye hug. Turned out to be much more as the two fused together in a brilliant light. When it faded, DBY was now a creature known as an Istrala, and learned all the knowledge and instincts of the enyo he had merged with.

What Didn't Change

Personality wise, very little changed. Cobalt gained a better appreciation to do what is right, but overall is the same. His coloration also generally remained similar, even if the rest of his appearance is different. The Sword of Balance remained connected to his being and is still the peculiar sword it was previously. It is incapable of causing harm or death, but will magically divide a being into 2 instances. Powers, abilities, and traits tend to be split between the two instances, and occasionally differ in gender. If someone is inhabited by multiple beings, it will split off one and reincarnate a body for that being. For inanimate objects, if the sword can cut or substantially nick something, it will magically split the object in half perfectly, usually symmetrically but can resort to other methods such as weight, mass, or volume.

What Did Change

Aside from coloration, his appearance in becoming Cobalt changed quite a bit. His overall size increased, now standing around 7 feet tall. As a result, the sheath for his sword no longer fits him and he now tends to summon it and send it away by magical means. His new wings provide him the ability to fly, which is something he has always dreamed of. While he gained flying instincts from the enyo, he occasionally has a rough time landing when under pressure. His tongue is significantly shorter than what it was as a yoshi, but still longer than typical istrala. His eyes now change color with his moods, such as red for anger, yellow for fear, green for love, and more. While this is new to him, he is decent at controlling his emotions and can usually keep his eye color under control. Intense emotions such as rage or surprise are harder to hide.

Ryusuta, the creator of Istrala, has publicly asked that they're not portrayed in a sexually-explicit way. With respect to this, no such content will be provided here. The only thing to say is that DBY was generally only attracted to females, and as such, Cobalt is also mostly attracted to females.