User blog comment:MarineroLelouch/Power Ranking and Classes./@comment-92.96.32.189-20140215151525/@comment-24066070-20140215201020

Of course I know it's unlikely for Ivan to kill a Dragon (he didn't seem very strong during the GMG)

I think those DS Lacrima are made by the Dragons. Sting and Rogue's parent likely transferred some or even all of their remaining magic into a Lacrima and gave said Lacrima to their kids to make them even stronger.