changing weapon elements?

What are the "certain items" that can be used to change a weapons element but i see no mention of in any guides?

I forgot the name on NA version but they are in the last category in your storage. I also think they are listed as a AC item as well. Each one will have the type on it (Light, Dark etc). When grinding a weapon bring the item.and can use it to change category

In the JP version they're called "Change Attribute (Element.)" (Where Element = Light, Dark, Fire, etc.) I believe they came from AC Scratch, or from the Swap Shop. I've never seen them drop. They're considered a "Support Item." Or an item used like ability success, etc.

Those items are called Elemental Transition (element name). The latest AC scratch has Fire, Wind and Light (https://pso2.com/news/announcements/heroicwanderer). The other AC scratches has different assortment of elements.

thanks for the help everyone