Possible racials for Ethereals:
Convert Cloth into Ethereal Dust to enchant your weapon with +1% primary stat for 1 minute. 2 min cooldown.
Transform in a Ethereal wisp for 10 seconds. This form is considered invisible for Humanoids, Beasts, Giants and Mechanical creatures. 30 min cooldown.
Experienced Ethereals (level 10 or above) don't have costs for sending mails.