It tickles my fancy the way Elidibus teaches us how the Echo awakens in people when they see the hail of fire of the End Days. Then Zenos talks about his dreams where he sees the world end in a hail of fire thanks to having been infused with a resonant.
It's the same way that Hydaelyn gives the WoL her power willingly, while Zenos' takes it from her dead corpse (just like his Resonant is made from dead people's souls). There is something in the way Zenos becomes a Warrior of Light in his own right (even saving the universe) without having a narrative that redeems him that delights me. There is no sob story where he suddenly sees the error of his ways. There's no need for it. He's utterly selfish and unsympathetic and still that doesn't change the path he walks and the result of it; he still becomes a warrior of light. It's exactly as he tells Alisaie: "Would you be 'happier' had I a 'good reason'?"
The narrative blatantly asks us: "what then, makes a hero? Their intention or the result?"
In everything, he's WoL's twisted mirror image.