Your +10 Armor can be upgraded to +20!
How do I upgrade an my Armor?
Upgrading Armor follows the same rules as normal upgrading. For each try you require a Powerful Angel Enhancer (Drop from Stratholme, enhanced at [Angel Shop] Gabriella).
aswell as an Angelic Upgrade Protect (Equipment) ([Angel Shop] Gabriella)
To upgrade the armor, visit BoBoChan in Flaris.
What are the benefits?
An armor piece can be upgraded further up to +20. Each upgrade level spanning all four pieces decreases the damage taken by 1.5%, for a total of 15% damage reduction if the entire set is upgraded to +20.