I'm going to take another crack at this. (Long post incoming.)

Name: Adi Merulae
Age: 22
Gender: Male
Current Occupation: Bounty hunter, janissary guard
Race: ¹/₄ desert spirit, ³/₄ human
Weapons: Adi perfers use of a scimitar, wielded in his left (dominant) hand. The blade is plain but very strong and high quality steel, while the hilt is wood treated to be fire-resistant. Tied to his belt is a simple dagger that can be used for both stabbing and throwing.
Appearance: Adi stands a little under 180 cm (which is about 5 ft. 10) and has a very athletic build from a physically demanding life. His body is deceivingly thin and compact, much like a runner's: to furthur this feeling, he is limber and flexible, although not excessively so. His skin is very tan, a result of spending his life in the desert. His eyes are a light shade of blue, similar to ice, and his hair is blond with a few streaks of very light brown in it. His body has scars over it; however, the clothing he wears often covers them up.

Clothing-wise, he generally wears the same thing he has all his life: white shirt and pants under a flowing gold robe. The robe's cloth was specially made to block out desert sun and heat, and the color was done for blending into the desert sands. Along his waist he wears a belt, which holds his sword and dagger sheaths, and he wears strong leather boots.
Personality: Very patient and bold, Adi is considered by many people close to him to be a born leader. He is obedient, but often finds ways to be creative and flexible while still under rules imposed onto him. Adi is also not afraid to make a gamble or uncertain move. However, he is a very untrusting person, perfering to keep to himself as opposed to being with others: due to this, he has a difficult time making friends. Furthermore, he is a very proud person, unwilling to lower himself very much. In times of necessity, he will do what he has to but as a general rule he stays away from stealing or cheating.

A very acomplished swordsman, Adi struggles to learn magic of any kind or sort. As a result, the only magic he masters is the spells that are unique to him and/or a few others; even then, only because he finds it a waste if nobody learns them. He is untrusting of any non-human races, despite being slightly mixed himself, or perhaps because of. Also, he is a very unromantic person and generally frowns upon flirts of any kind to anyone.
Background: Adi was born to a wandering tribe in an empty and dry desert. Due to the harsh conditions of the desert, he was raised from youth to be a strong warrior. Upon taking up his first hunt, however, the tribe discovered a seemingly fatal fear in him: fear of the cold. When hunting in the desert, warriors often have to camp overnight without a campfire while the temperature dropped down horribly low; unfortunately, Adi couldn't bear such low temperatures.

Deciding that keeping Adi would weigh down the tribe, the tribal leaders--after attempting to "correct" his weakness--threw him out into a particularly desolet part of the desert. The first night out without his tribe, Adi almost froze to death; soon, however, he overcame his fear of the cold simply out of sheer necessity. At first, he survived on hunting small animals that roamed the desert at night. Soon, though, he realized that without the support of his tribe he wouldn't be able to hunt large enough animals to survive, and would die. Desperate, he began to prey on other people.

Targetting lone riders going through his part of the desert, Adi either forced them to leave their supplies or--occassionally--killed them. Several times, he had to fight with someone who knew a bit about self-defence. Before long, he was a great swordsman from fighting and an expert runner from chasing people on horseback. Finally, though, the state government that technically controlled the desert sent a squad of elite soldiers after him. That day, Adi fought as hard as he could, but was overwhelmed by sheer numbers. Knocked out cold, the soldiers took him back to the capital.

Back in the capital, Adi was surprised to learn the king wanted to see him personally. The king gave him a decision: serve for two years under him to pay back his five months of breaking the law, or suffer imperial justice. Adi decided to serve the king; from then on, he served as an elite guard, protecting important government officials in their travels across the desert. After his two years were over, he left the capital, seeking his old tribe to see how his old friends were doing. Once he found his old tribe, the tribal leaders offered to re-adopt him; he refused. Although he knew what the leaders had done was necessary, he could not quite bring himself to forgive them; before he left, he visited his parents.

Once he found his parents, they told him a secret that previously, only they had known: he grandfather off his father's side was a desert spirit. All of the known desert spirits had been killed by the government for protesting against the takeover of the desert, but his grandfather had married and had a child with his grandmother. Adi's parent's told him that if he could learn spells unique to the desert spirit line, he would be much more powerful. Immediately interested, Adi set off for the capitol (once again).

At the capital, Adi searched for a mage who he believed would be able to teach him the spells of a desert spirit. He found the imperial mage who agreed to teach him the spells in return for a Adi's letting him research the effects of the spells for a week. Adi agreed, and the imperial mage began to teach him. During this time, Adi found out he was a horrible magic-learner, but he eventually master the handful of spells associated with desert spirits. Fortunately, the reserach the imperial mage did turned out to help him understand the spells much better and use them much more effectively.

Soon, Adi returned to the service of the king; when not serving the king, he was a bounty hunter, hunting down bandits who did things much like what he had done before.
Talents/Abilities:
Left-handed (pretty self-explanatory)
Whistling/bird-calling (also self-explanatory)
Desert spirit spells
         Most desert spirit spells he knows involve the transfer of heat. The amount of heat he is transferring/removing is porportional to the amount of energy that is drained. For example, to heat up his entire sword (a favorite trick of his) takes around the same energy as to lift something moderately heavy. The amount of energy also depends on how far away the object is and/or if there is something in between him and that object. If he were trying to heat up an enemy's sword (if the enemy was several meters away from him) would take almost twice as much energy.

His background gets kind of klunky around the end, I think that at that point you probably just wanted to get it over with, which I understand wholeheartedly. Don't forget to check, spelling etc.

Solid character IMO, though you may need to further emphasize the harsh cultural society of the tribe, or make an early note of his parents treatment of him. Until the whole mentioning of his lineage I was beginning to think he was orphaned or something. Personally, I like to deal with the family (or lack thereof) first when dealing with their background.

There seem to be quite a few contradictions as well. Such as him being a born leader but not wanting to interact with people, or the king allowing someone who had spent five months robbing and murdering travelers to get close to him and other important persons. I'm also a bit confused about his clothing. It doesn't seem like the kind of thing that would be afforded to a tribal reject, and one would think that an elite guard would have their own standard issue uniforms.

My thoughts exactly >.>

Though on the personality thing, people are comprised of multiple contrasting though co-existing traits. Different situations can make someone who is outgoing, reserved while in another state of mind.

I'm not sure how close they were, but I can see the problem.

Yeah, I got a bit impatient at the end.

I'll keep that in mind.