He does not judge people when he can help it, just like his counterpart, but he does judge goals. If they conflict at all with his own, he will have no regrets abandoning them or intentionally destroying any chance of success for the conflicting objective.
So in a manner, he's friendly. But he's not looking to be your BEST FRIEND FOREVER. Just to see you do something that makes you smile and forget pain until he finds a way to end it for good.
Now I've done all this writing about Koli's past and such, but there is something vital to the character that I have neglected to mention. Koli is the very personification of some of Kilo's worst nightmares. Kilo, having stored a large amount of access magical energy due to not using magic, successfully created a materialized form of Koli in his sleep. Kilo's magic was restored back to normal condition for this, but Koli exists within the same realm as Kilo, bearing the same nightmarish memory of his past as he did within Kilo's dream. And realizing Kilo is his reason for prolonged existence rather than a transitory one, Koli begins to loath his counterpart.
However, the existence of both within the same realm was rather problematic for a time. The two, being fundamentally the very same person, look very much alike and are often confused. Because of this Kilo is sometimes blamed for things Koli does, and vice versa.
Between the two, there are some less obvious similarities. They're both a bit more frail than the average Sabrecat, and a bit effeminate and creepy. Both have strong feelings for balloons and things of cute nature. However, Koli, being the physical manifestation of excess magic and nightmares, very seldom draws from magical energy unless he has a very good reason to, unlike Kilo who often experiments with magic for entertainment.
But the reason is simple. Because Koli IS a manifestation of magic, using magic is, in essence, using his life-force and therefore suicide.
In direct contrast with this is the fact that he can exercise nearly godly control over the air and gases all over. Including that within balloons, the general surrounding, or that within another living being. He could indeed forcefully suffocate a creature by depriving it of air or expand it to bursting by filling it with excess air. He could use a strong gust to blow one a long distance away, or concentrate the pressure and movement to a very limited area and use it as a means to tear solids from its surrounds (In a manner of speaking, he could use it as a blade). But once again, drawing on this power would drain him to the point of death, and it would hurt him very much to do so, so he resists it when he can.
Kilo's magical abilities are nothing like Koli's. Which he can do some things with them that may seem impressive (animating a balloon modeled after another creature to the point of seeming alive) he couldn't actually do much harm or good with his abilities. Kilo's healing spells are painkillers, and his other spells being little more than entertainment ruses that serve little other possible purpose whatsoever.
If Koli and Kilo were to fight, it's very unlikely that Kilo would survive without outside assistance.
It's worth noting that Koli does not have the benefits of natural inhabitants of Sabrous, and if killed completely, would not come back to life at a temple. However, as long as a shred of mana exists bound to his soul, he'd be unable to die by conventional means.