[What is the actual item/mechanic/thing being targeted?]
Shadow Armor
[What would you like specifically changed about it?]
Shadow Helmet: 18 defense, +6% damage, +3% extra summon damage
Shadow Chestplate: 25 defense, +8% damage, +3% extra summon damage
Shadow Greaves: 20 defense, +6% damage, +3% extra summon damage
[Why do you feel that this change is needed?]
Shadow armor would serve nicely as a lower defense, slightly more offensive (to melee/whips) counterpart to the Crimson armor. If you think about it, it could be a greatly less unfair Obsidian Armor for all devices, that supports all classes as well as summoner.
[Anything else you would like to note]
If it does anything, take into account the +15% movement speed set bonus.