How to use stones

There are different kinds of stones which are acquired after battle but there is no such direction how to make use of those stones.... I am new here so please tell me how to make use of those stones.

When you reach the maximum level of your item when upgrading using gold for example your equipped sword, then this is the time where you can actually use the stones. You will be notified what kind of stone that will be used to exceed the maximum level of the item. For armor - iron stone. For sword - yellow, red etc. Hope this helps

Another thing upgrade your pet dragon so you can use the stones, if you want ...

Powerstones come in different colors such as green,blue,red,and yellow these can be used with a weapon with the same attribute such as yellow with lightning and red with fire you can also use some of these stones to upgrade your pet dragon if you so choose.