Anrakyr the Traveller
Anrakyr the Traveller is a Necron Overlord who upon reactivation decided to renounce government over his domain in order to travel the galaxy to help reawaken the Necron Tomb Worlds which were still dormant, fighting possible interlopers or avenging destroyed Necrons if they were overwhelmed before he could help them. Think of him like a Necron Gandalf.
While he is utterly ruthless whenever he finds a lesser race sacking a dormant Tomb World, he has shown to wield a code of honour and spare the defeated enemy, offering honourable terms of surrender and even, perhaps, a sort of compassion.
For example, there is this short story in the codex where he had captured a defeated IG colonel, he was supposed to hand him to Illuminor Szeras, most surely for painful and slow experimentation, when meeting each other in person (something which may not have been necessary) the colonel spit upon him, defiantly claiming that the Imperium will send more forces, Anrakyr, instead of handing him to Szeras, killed him on the spot. While this may have been to simply annoy Szeras for having used Deathmarks without his consent to win the battle, it may well be that Anrakyr didn't want the colonel to face a horrible fate as Szeras' guinea pig.
Opinions of the Necron nobles over Anrakyr are divided; most of them consider him an honourable warrior dedicated to help the survival of their race, others (who won't give them the tribute of soldiers he requests from a tombworld after liberating it) consider him a menace as he invariable takes his tithe, even if he has to steal it.
Anrakyr has technopathic abilities, allowing him to take control of vehicles he happens by. For example, in aforementioned story above he seized control of a Leman Russ Battle Tank and after briefly pitying its flawed design holding back its full potential made it fire its weapons on the remaining Guard forces.