I've been thinking of all these story ideas with Echo and Noiz. The alien thing is getting SO interesting.  
Echo's a boy but Noiz probably switches genders/ dresses androgynously a lot. (likes being called a girl but knowing her she wouldn't even care if you called her a boy?)
I think the term is genderqueer?
I mean it's nbd, they're basically dittos.
 
Also every time I draw Echo he's starting to look more like Silver OTL