Upgrade

Upgrading your weapon allows you obtain stats much higher than it's predecessor, often coming along with notable visual changes. While this requires normal runes and gold for most weapons, special runes may also be required for both event and epic weapons.
Upgrading generally increases the grade of a weapon, which is not be confused with rarity. Higher rarity items have more grades you can upgrade to. The table below uses a weapon's initial grade as an example, which denotes how many times a weapon can be upgraded.
Grade 	Epic Weapons	4* Weapons	3* Weapons	2* Weapons
Maximum Grade	5 	4 	3 / 4 	3
 Here's an example of an upgrade interface: 
 
Do note that a weapon must be at it's maximum level before it can be upgraded, which is reset upon doing so. Thus, don't forget to enhance it again!