Elysa Varbolt, Ashley Ryltan and the Tyrathlion surname are all from old stories I wrote, way before I started Eve. For some reason, I didn't use the original Tyrathlion name and just went with Mortis. I was coming to Eve from Freelancer, where I had been an irrevocable pirate, and... eh, just felt like something kind of menacing.
Repentence was the first character I created after I started RPing. I did have an industrial alt (who is occasionally mentioned, but I don't RP with), but I wanted to take advantage of the double-training-no-SP-start thing, so I conjured up the story of Mortis' black sheep troublemaker little sis. I was pondering on what kind of a family would call their son 'Mortis', and came up with a fairly pious bunch. Thus, I eventually came up with the four Tyrathlion siblings - Mortis (born Judgement, incidentally), Purity, Charity and Repentence. Purity has appeared very briefly, and Math'ra shudders to this day after his encounter with Charity.
And yes, I know 'Repentence' is mispelled. It's a proper name, I'm allowed
On a more obscure note, the name of the entity that ambles around in Ashley's shell, the Masque, is a Warhammer reference.