Aggregate Armor

Requires attunement. This armor has 2 charges. While wearing it, you can use a bonus action to spend charges, giving it a bonus to your AC for 1 minute. The bonus equals the number of charges you spent. It regains 1d2 expended charges daily at dawn. When you expend the last charge, roll a d20. On a 1, it becomes non-magical armor.
If you expend all two charges at once, roll a d10. On a 1, the armor overloads with energy. The creature wearing the armor takes 1d12 force damage.