Taken from the Githyanki of Dungeons & Dragons, a Gish is an individual who blends some form of supernatural power usage with a mundane professional skillset to create a hybrid professional archetype. In RIFTS, we see this most obviously in the form of the Cyber-Knight and less so with the Operator (and an argument can be made for the Crazy, since so many are psychic), but the pattern holds: these Occupations blend psychic powers and professional skills into a hybrid that exploits the synergies between the two. To return to comparisons to Marvel or DC characters, we're now looking at characters such as Cable, Deadpool, Deathstroke, and others that are often supersoldiers; rarely, alas, do we get further than that in the comic world.
The way to approach a Gish is to remember that the whole is superior to the parts, and that means that a Gish is someone who spent considerable time prior to entering gameplay undergoing some form of training or apprenticeship wherein he not only learned both of these parts, but blended them together into a coherent and synergetic paradigm. Like the Psychokinetics and Telepaths, Gishes come to build their identity around their abilities; unlike those two, Gishes are made, not born, and therefore enjoy a stronger resilience psychologically when something happens to nullify one of those parts. A Cyber-Knight without his Psi-Sword and Sixth Sense is still a skilled warrior; he can pick up a Vibro-Sword and still make use of his swordsmanship skill, and technology (along with deep mastery of mundane skill) can compensate for his lost Sixth Sense. (Ditto with Psi-Warriors, Crazies, etc.) An Operator is still a competent engineer, mechanic, technician, and tinkerer without his Tele-Mechanics powers- other examples exist.
This means that you're playing someone who finds mundane people relatable, sometimes in a paternalistic manner and sometimes not, but rarely are we dealing with the disconnection of empathy that often happens with Psychokinetics and Telepaths. Yes, even if your man is Selfish or Evil, he still finds ordinary people relatable; he may regard them poorly, and see them as suckers to be fleeced or cattle to be herded or culled as needed, but the God Complex issue is rarely a problem because he remains fundamentally tied to ordinary people in a way that Psychokinetics, Telepaths, and other similarly-powerful archetypes often lack.
The other thing is that Gishes, due their training/apprenticeship background, appreciate the value of cooperation and teamwork due to having multiple perspectives built into that process. While they can, and some prefer, to work alone they rarely insist upon it as a routine matter; evil Selfish and Evil Gishes will cooperate with others to accomplish their goals, and appreciate deferred gratification sufficiently to think beyond right now and instead prioritize objectives such that they can delay or avoid betraying today's allies (Why do that? It reduces or eliminates needless complications; if you don't need to stab in the back to get your way, then don't- effective villains are not the proverbial Scorpion.)
So, if you want a more humanistic psychic character, look into playing some form of Gish. Ditto that if you want a psychic character who isn't wholly dependent upon his powers to be effective. The Cyber-Knight and Operator have their fans for very sound reasons, reasons that extend to all characters who blend power and prowess as they do. If you haven't, try one next time.