I had this track in my scrap folder for a long time.

I tried to make a battle theme similar to FFVI's "Decisive Battle"

Do you have any tips about how to create a battle theme or to avoid dead-ends while composing?

Your melody is pretty active. And it only plays once then goes into something else so it's hard for your listener to get settled. Consider your inspiration/reference track. The opening riff plays 4 times at the beginning while the arrangement around it changes and evolves. Then an adapted version of the melody plays through twice. 

What I would try and do is simplify your melody and build up an arrangement that showcases that over a bit more time. Your actual sounds could also use a bit more producing as the samples are not that great. That will help inspiration as well. Spending a bit more time studying how other tracks are built up and composed will also help. Best of luck! 

Hope that helps!

Nate