
Kent is the play's clearest embodiment of unconditional loyalty - banished for defending the daughter who told the truth, he returns in disguise to serve the king who exiled him through every subsequent catastrophe, asking nothing in return, which is precisely the love Lear failed to recognise in the opening scene.
Kent is the first man in the play to tell Lear the truth to his face, and he pays for it within moments: seeing the king about to disinherit Cordelia for the crime of honesty, Kent argues against him so plainly - 'be Kent unmannerly / When Lear is mad' - that Lear banishes him from the kingdom on pain of death, in the same breath and the same fit of temper that costs him his youngest daughter. It is the clearest possible demonstration of the play's opening irony: the two people banished in the first scene are the only two who loved Lear without asking anything of him in return.
Rather than accept the banishment, Kent disguises himself - rough dress, altered speech, a new name, Caius - and returns to serve the king who cast him out, a loyalty so absolute it borders on the self-erasing. He fights Oswald in the road for his disrespect to Lear, endures the indignity of the stocks at Regan and Cornwall's order without breaking his composure, and stays at Lear's side through the storm on the heath, urging him toward what little shelter can be found, one of the only steady presences in the king's disintegrating world.
Kent's loyalty never wavers and is never fully repaid: he reveals his true identity to Lear only once the worst has already happened, and by the play's final scene, with Lear dead and Cordelia dead and the kingdom in ruins, Kent speaks of a summons he must obey and will not long survive - his master calls him, he says, and he must not say him nay. He exits the play as he entered it, a man whose devotion asks for nothing and receives, in the end, only the chance to follow where loyalty leads.
Kent is motivated by a loyalty to Lear that survives Lear's own injustice toward him entirely intact - he does not serve the king because the king deserves it in that moment, but because service is simply what his devotion requires of him, regardless of reward or recognition.
Kent's defining quality is a bluntness that will not soften itself even to save his own position - he tells Lear the truth in the opening scene knowing exactly what it will cost him, and having paid that cost, returns anyway in humbler dress to keep serving. His courage is not the courage of the battlefield but of unwelcome honesty sustained through disguise, exile, the stocks, and a storm, without ever once seeking credit for any of it.