How to get the secret treasure from boss 4

[number12th]

The Zephyran boss?

[tech7]

You mean the wyvern ? It has two horns which can be attacked, if you destroy them before you kill it, you get the Secret treasure.

[MithranArkanere]

You should use the cycle buttons to target the horns after selecting its body. Selecting the horns directly is way harder.

Remember to pick the treasure before finishing off the boss, or you'll have to start all over again... like I did by accident. ¬¬U