sepia is ok, other than a bit too yellow for my taste. However, it seems the sky has been blown out and you need to balance it a bit. Was this meant like a test piece?

I do. but yeah, the sky is a bit too bright to my liking

This image gives me an impression with the sepia that there is fire to the L of the photo and the clouds are actually smoke. Vivid imagination, I know. :) Sepia can be nice, to me it's a different type of black and white. Nice job.

I feel you have made what would have been a dull color picture far more interesting by the use of sepia.

if this is what you were seeking for your end result. Great shot!, if not I agree it is to bright. Darkness would have given more mystery to it.