From my view, they both appear as if they were 'kre8tivlee' made-up (particularly Katrelle); which does not attract my positivity. The latter seems relatively harmless and tolerable; there is a chance that Katriel could work... though it stills seems terribly juvenile to me.As a note, both names would likely conjure up the thought of The Hunger Games... isn't there a character similarly titled "Katniss"? The names within that series, from what I have witnessed, are slowly picking up admirers in the real-world, too. With the current obsession, Katrelle/Katriel could potentially come off as an inspired variant of Katniss (which I would easily believe possible.)- Francesca