Aichmomaniacal Scales

Through chance, or savviness, you noticed your daggers can act as a makeshift form of armour. This has become an obbsession and you find yourself compulsivly finding new areas to stow your blades. 

Your character now uses daggers as armour.

• Depending on the quantity of daggers carried your AC will be increased.
• This feature can stack with padded or leather armour at low levels.
• Donning and doffing of this type armour takes extra long
• If the daggers which are used for armour are lost, temporarily in combat or otherwise, and the amount drops below half way to the previous tier, the armour degrades to that tier. (for example 23 daggers would degrade you to the 3rd tier) but upon regaining the necessarily amount no extra fee or skill check is necessary.

Finding how to store so many sharp objects is difficult. 

• Before upgrading to the next tier of armour the player must either spend 10 (or more) GP or create appropriate facilities using tools, skill checks or feats. 

Your character has noticed the benefits of using daggers as armour.
Tier1 [11]: Your forearms and parts of your chest are vaguely protected
+11+ Dex
-10+ Dex if damage type is piercing
(+1 AC to leather or padded armour)

Tier2 [17]: Your arms and parts of your chest are vaguely protected
+12+ Dex 
-10+ Dex if damage type is piercing
-1 on stealth rolls
(+1 AC to leather or padded armour)

After tier 2 you character can deploy up to 1 dagger sized weapon per turn as a free action without it being considered an interaction.

The Obssesion grows and has manifested an arcane property. Your character finds themselves utterly obsessed with their daggers.
Tier 3 [21]: Your arms and parts of your chest chest are protected
+13+ Dex AC 
+1 on damage rolls with daggers
-11+ Dex if damage type is piercing
-Disadvantage to stealth
(Replaces armour)

Tier 4 [28]: Your arms and most of your chest are protected
+14+ Dex AC
+Advantage on attack rolls when using daggers
+2 on damage rolls with daggers
-Vulnerability to damage from daggers
-Disadvantage to stealth 
(Replaces armour) 

Optional at level 5
Your obbsession has become an integral part of you. You have a deep bond to bladed weapons
Tier 5 [30]: 
+14+ Dex AC
+Advantage on attack rolls when using daggers
+3 on damage rolls with daggers (+10 if the character has killed an enemy within the previous current round)
+3 on attack rolls with daggers (-5 if the character has killed an enemy within the previous or current rounds)
-Can only use daggers for attack rolls
-Vulnerability to damage from daggers
-Enemies using bladed weapons gain advantage to attack rolls
-Disadvantage to stealth 
(Replaces armour) (only ac degrades, buffs and debuffs remain)