I don't know if its intended or not but you can use certain skills in stealth that do not break Stealth, this is for all classes with stealth not just ranger.
With Ymir on the skills break your stealth and without ymir on you remain in stealth lol....
Skills that worked in stealth -
True sight
Wind walk
Acrobat
Edited by Fluidz, 03 December 2014 - 10:23 AM.