So, you may ask yourself this- Why are sting and Rouge so weak? Truth is I don't know, but I can tell you why they should be more powerful than all the other Dragon slayers. Sting and Rouge learned DS magic EXACTLY like Natsu, Gajeel, and Wendy until they killed their Dragon, then bathed in the blood gaining the ability of Dragon Force, this is how Acnologia gained more power 400 years ago. So by this point Sting and Rouge are the closest things to a TRUE Dragon Slayer, to take it even further than that they became the FIRST 2 augmented Dragon Slayers by taking the Lacrima within their dragons and implanting them within themselves! This gives them the advantage of more Magic energy that they can use during fights. And lets not forget that Second Origin is a tad BS
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