There are multiple items you can use in Pokemon Brilliant Diamond and Pokemon Shining Pearl to make your Pokemon stronger. However, items like Shell Bell can help you survive fights for longer because of its healing power. Below is the location and how you can get the Shell Bell in Pokemon Brilliant Diamond and Shining Pearl.
Shell Bell Location
You can find the Shell Bell in Hearthome City. Go to the Hotel in this area and use the elevator to get to the top floor of the hotel. After exiting, you will find an NPC with green hair sitting on a chair.
Talk to this NPC and they will tell you that they have an item for your pokemon to hold. They will give you the Shell Bell.
What is a Shell Bell?
A shell bell is an item that can be held by a Pokemon. The holder of this item will recover a little bit of HP. You can only activate this skill if your pokemon inflict damage on enemies.
This item will restore 10% of the damage caused to your Pokemon. Keep in mind that status effects like Poison or Burn will not work with this item.