I have upgraded my metal piecer to max (epic) however I cant fuse it, all the time and effort I put in this weapons to just go to waste . There needs to be another tier to this weapon! Please.
Before you upgrade, see the dots below the item name. Purple means epic, yellow means legend and orange means myth, only upgrade those weapons which have yellow and orange dots also ( along with the other dots) it means when you upgrade it Can be upgraded upto myth status
Here is a picture arrow pointing to what you need in an item to upgrade further than EPIC to coincide with what Merciful said.
This item will upgrade from EPIC to LEGENDARY to MYTHICAL, these are the items you want to upgrade if you have them that is.