A powerful psychic, Kuprum is well aware of what his exceptionally powerful abilities might land him on Alternia, though he is thrilled at the prospect of being used as a battery. Kuprum's personality seems to be based on 4chan culture, most likely the /pol/ ("politically incorrect") board, as he seems to favor the empire and Trizza, (even being "thrilled" at the thought of what happens to powerful psychics. This is furthered by Folykl mentioning his addiction to "eastern alternian pornography", a reference to hentai, which 4chan is known for as well. His typing quirk reflects this, as putting greater-than signs in front of messages on 4chan is known as "Greentexting," (As it makes the text green) and is used on the site for multiple purposes, including quoting another user's comment.

He also seems to enjoy pranking highbloods, due to his dislike of them in general. Hacking into their mobile devices doesn't seem to be much hassle for him, and he was able to key in the wrong directions so that the group of blue bloods would wind up hopelessly lost in an unfamiliar part of town. While Kuprum later vehemently insists that his prank was actually a declaration of war, he does not really inflict any sort of harm upon the blue bloods. This can either mean that he had yet to make a move, or is still somewhat hesitant to outright attack those he deemed as enemies.

Despite regarding the highbloods with open disdain, that does not mean that he sympathizes with the plight of his fellow lowbloods. This is best illustrated when the player (mistaken for a redblood) mumbles something about bad luck and having no place to call home, Kuprum ridicules the player for being homeless and losing their lusus. He later reveals that he views everyone as idiots regardless of social standing, so that may play a part in his apathy towards the oppressed. It is also suggested that insulting the intelligence of others is what he and Folykl do all the time. 

While not an overtly pleasant person to be around with, Kuprum still cares about Folykl and to a lesser extent, the player. This is evident when the Imperial Drone begins chasing the three of them: Kuprum uses his psychic powers to levitate him and Folykl to escape, and after a bit of consideration, levitates the player as well. When they run right into the clutches of another drone, he immediately flings everyone out of range before the drone took aim. Even though Kuprum winds up being briefly separated from Folykl and the player, he rushes to defend his moiral from impending doom by frying the drone's circuitry with his psionics. After fussing over Folykl's wellbeing, he then turns to the player to check whether they're alright too.

As a lowblood, Kuprum is not obligated to speak in a formal manner, so his speech is casual and peppered with swear words. He also insults the player (and probably everyone else) quite frequently, using just about anything as cannon fodder for taunts and mockery.

I'd imagine him sounding like Pink Guy from the Filthy Frank Show. Example: https://www.youtube.com/watch?v=FN3CYsumqRE