This card is very good, but I also think it could have an attack + 5 | + 6
The attack itself can be buffed by raging themselves.
The fire element is full fury, with rage would be 11 | 1 UP 13 | 1
Please compare to the dragon.
well, the dragon comes into play with 10
and 12/3, the nymph with 8
6/6, second turn nymph pays 3
gains +5 and loses -5
the total was 11
, more expensive and slower and weaker than the dragon.
clear that the nymph destroys creatures with less than 6 of defense the dragon has not this hability.