New resorce! Blacksmith!

The blacksmith would take you're troops wepons (of you're choice) and upgrade the wepons, it would have the upgrading cost of 100 gold coins, making it more powerful than the last upgrade, it would increase damage and sometimes have special effects, it would go up 300 coins each upgrade and the maximum upgrade is level 10, it would have 10 seconds each time, all it would do is upgrade wepons of your troops, not the actual troop. The damage would increase by 20% each time upgraded. This would not apply to giants or any troop with no actual wepon.