(to those who may think this price is 'unreasonable': I would buy it straightaway for 4b if I really wanted to benefit from a completely-done dark drone. Do not underestimate the cost of fairy-building 
I know I must have been unlucky but I wasted 4b just to get atk%, just this one option, on my water drone. I had to use 27 fairy restoration sets for this one single option at +7. Wasn't even going for S or +8/9)
#WTS {Shadow Element Steam Drone}
rotund topaz
final light
1$