As for Aide, she is all personality and very little backstory. Nowhere near as detailed a history as I did with Hollins’ design.
She is mostly inspired by tropes on the TV Tropes website and various people in my life who are noticeably positive, cheerful, humorous and/or light-hearted.
The main aspect of her backstory that I put time/effort into, is her family. Most of her siblings have met a tragic end already. 
As a blood elf I wanted to reflect the massive losses sustained by that race and how their lifestyle and bloody history influence their mindsets.
So, to paint that contrast more clearly for myself (and to make things a little more dramatic) I also fleshed out and occasionally roleplay her mother, Timenora, who is Aide’s radical opposite in one trait:
Seriousness.
Aide takes nothing seriously enough. Her mom takes everything way too seriously. 
(See here [BElf-RP Farstriders] The Blood Ravens 🏹 - #96 by Aide-argent-dawn)
It makes Aide refreshing and joyful to play, as she’s an eternal optimist and shrugs off the most awful things, carrying her fellow Farstriders through hell if she has to. But she’s not quite serious or level-headed enough for the job.
Easily distracted and all.
Far from good soldier material.
But who could resist that optimism and commitment?