From Wiki, sounds like a good analysis of this steerpike:

Steerpike might be called the antagonist of the Gormenghast Series, but in truth he is more of an anti-hero; the first book for example is largely focused on him, only covering the first year of the titular hero Titus's life. Steerpike could also be considered an archetypal Machiavellian schemer: a highly intelligent, ruthless character willing to justify any and all means to reach his end. In the books, Mervyn Peake describes his personality as follows:

If ever he had harboured a conscience in his tough narrow breast he had by now dug out and flung away the awkward thing - flung it so far away that were he ever to need it again he could never find it. High-shouldered to a degree little short of malformation, slender and adroit of limb and frame, his eyes close-set and the colour of dried blood, he is climbing the spiral staircase of the soul of Gormenghast, bound for some pinnacle of the itching fancy - some wild, invulnerable eyrie best known to himself; where he can watch the world spread out below him, and shake exultantly his clotted wings