Multiple Special Effects... How to remove them

[Starmaart]

Yes, me and my friend, we are trying to make a sort of loap game... But would there be some kind of trigger like:

"(Last Created Special Effect) = Claws_ATK"

... because we did find :

"Set Claws_ATK = (Last Created Special Effect)"

but that one won't work...

(The Idea here is to buy an item... Which gives you a helmet or something... But if you sell, or lose this item... To destroy that special effect. There are multiple items ... So multiple Special effects, and they can't all be getting the line "Last Created Special effect" Do they?

Any help would be appreciated,

Starmaart and his friend