Help on a possible craft (1H axe)

I found this axe today and am wondering the best course of action to make it better. Crafting is not my forte.

It has 3 suffix already so I know my only options are to get the 11 remaining prefixes available to me. I was thinking master mod some prefix I don't care for and that's common like cold/fire/light damage and then exalt slam it. In turn then exalt slamming it again after removing master mod. Would that be best course of action? As of now its 400 pdps so def could be better. Not too sure this base axe would be worth it as well. Any insight appreciated.

Thanks!

I'd stop right here because the base item (royal axe) isn't top tier.
The attackspeed is just too low, there may be better axes with ~350 DpS, just because they benefit from flat physical on rings and amulets.

But if you want to gamble an exalted orb, then do what you described.
Block some shit prefix, slam in hope for high tier flat phys or hybrid %phys.

If shit prefix, go back to mastercrafting flat phys.
If low tier flat phys, bricked.
If great prefix, congratulations.

Slamming it twice sounds like a bad idea to me, unless the first slam was high tier flat phys.

Thanks a lot for your feedback man. Greatly appreciated.