Reinforce Item
With this item you can give an item with additional bonuses. You can combine the item you want to strengthen and the 'Reinforce Item' item by clicking one of them and dragging it onto the other. The process does not always work though. Items can be strengthened with up to four bonuses using this process.
You can buy this item in the item shop with Dragon Coins.

Enchant Item
Next to the item 'Reinforce Item' you can use the item 'Enchant Item', with which an item can be enhanced with new bonuses. When you combine an item with the 'Reinforce Item' item, the bonus is removed from the item and a new one is added. However, you will not know in advance which bonus your item will receive.
You can buy the 'Enchant Item' item in the item shop with Dragon Coins.

Spirit Stone
Spirit Stones are not just used for decorating weapons and armour, but they also strengthen the abilities of their wearer. Some can only be used for weapons, others can only be used for armour. However inserting a spirit stone is not easy as it can break and lose its power.
You can insert a Spirit Stone by clicking on it and dragging it onto the appropriate item.
The following Spirit Stones can be used for weapons: the Stone of Penetration, the Stone of Deathblow, the Stone of Cooldown, the Stone against Warriors, the Stone against Ninjas, the Stone against Suras, the Stone against Shamans, the Stone of Monsters
The following Spirit Stones can be used for armour: the Stone of Evasion, the Stone of Ducking, the Stone of Magic, the Stone of Vitality, the Stone of Defence, the Stone of Haste.
The level and the quality of the Spirit Stones varies between +0 and +4. Depending on the level of the weapon or the armour, up to three Spirit Stones can be used.
You can find Spirit Stones in the game or you may receive them as a reward for completing quests.

The Stone Handbook
If a spirit stone splits, it loses its power. The weapon or armour can still be used, but one of the spirits stone sockets will be blocked. If you find a new spirit stone that you would like to use for a weapon or for armour, you have to remove the split stone first. If you click on the stone handbook and drag it onto the item with the blocked socket, you can remove the split stone.
You can buy the stone handbook in the item shop with dragon coins.

Spirit Stone Scroll
You have inserted spirit stones into an old weapon or old armour, but would now like to use them for a different item. You can remove spirit stones from a weapon or from armour with this spirit stone scroll. To do this, click on the spirit stone scroll and drag it onto the item from which you would like to remove the spirit stones. The spirit stones that you have removed will be put into your inventory.
You can find the spirit stone scroll in the game or you can receive it as a reward for a completed quest.