Windhowl, Common 1g
Aria.
If Enemy Dungeon < 5
Enemy recruits: -2 + #Aria in hand
Do you really mean to add the #Aria, or are you subtracting them as well? As written, having 2 Aria would cause nothing to happen because -2+2=0. If you mean to subtract them (2 Aria means enemy recruits: -4), you need to rephrase the math sentence.
I suggest revising the card this way for clarity:
If Enemy Dungeon < 5
Enemy recruits: -N
N = 2 + #Aria in hand