no the only reason shandris has blue skin is beacuse she is a night elf the reason that sylvanas has blue skin is that she is a banshee
and the reason that amara has blue skin is that she also is a banshe but because of her powerful dark powers she gained a real body much faster than sylvanas did
Basically all elves turn into banshees (only girl elves) when they die. The male elves have blue skin, but its a less blueish tone. I think this campaign could be interesting, mind if I helped you skin? (pm me).