Board Thread:Tips and Tricks/@comment-94.98.72.141-20130602190134/@comment-3271569-20130602215124

Let's check,
 * Primary Metal
 * Secondary Dark

So:
 * not recommanded elements
 * Recommanded primary
 * Electric:
 * Dark:

--- So the best counter dragon is an dragon with an primary element electric or dark.

Now check the second element: Dark

So you can choose between these hybrid to counter him:
 * Electric/Dark (neon, block, mummy)
 * Electric/Sea
 * Electric/Nature (gummy, ...)
 * Electric
 * Dark
 * Dark/Sea (pirate)
 * Dark/Nature