well to behonest the move could just ignore stun all together since eruption can be dodged with out having to stun the cast as the target is selected upon start of the cast we just don't get a visual que be its easy to tell who is going to get bombed. It really is just a gift via the design you know like phoniex downs dropping zombie type mobs in one success in previous final fantasy titles. It can be done in other ways but the majority likes to follow the color by numbers approach as did nael van darnus in 1.0 but the fight is overall much more forgiving now then it has ever been in its previous incarnation which makes me wonder about the stun "requirement" or gtfo