December reveals Ros's secret.  The party is shocked and glad to hear it.  But Ros seems unhappy, and December thinks he knows why.  He says that if Ros uses his power it will revive the Demon King, and so he orders Juli to attack again.
You used your power for a second back 
there to dodge Juli-kun's attack.
Hace un momento utilizaste 
por un segundo tu poder para
Hace un momento lo has utilizado para
Você usou seu poder por um instante
 para desviar do ataque do Juli.