Niyleen Flame-Child was already a well known and well respected Mercenary in the Reach when Aria Lustfal Bal showed up, tougher and more battle hardened it quickly became clear to Niyleen that Aria would be competition for her and she had to remain the top Mercenary in the Reach. Over the years Aria and Niyleen would work on odd jobs together while not thrilled by this they both put up with each other till the Job was compete and whatever happened after was between them.  Eventually after taking on a dangerous contract together Aria and Niyleen both found a new found respect for one another, understanding what they had gone though together they're hostility towards each other faded soon after.

 

Eventually Emily Heavy-Iron a good friend to both Aria and Niyleen helped the two of them find common ground and become friends, when Aria has work in the Reach she contacts Niyleen first and offers to split the payment and Niyleen does the same for Aria in the Rift.

The two are now good friends and have each other's back when the time comes

 

Aria: Niyleen and me go waaaay back, shes like a third cousin or something I guess

 

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