i want to Create a Custom Eatable Item which gives Custom Abilitys Please Help!!!1

Hello, a Friend of me and I want to Create a "One Piece Mod" Where you eat special Fruits and after you ate them you get special Abilitys...

So heres my Question, how do i get a custom Gui after i Ate the Custom Fruit and can do special abiltys (multiple abiltys)...

I already finished the Abiltys and Put them on Bows, but they can only carry 1 Abilty, i hope for an Answer!!! Thanks!!