I made a general elemental chart for the DBZ RP for elements. Here it is-
As you can see I separated them into 3 classes.
Solids: Plants, Earth, Sand, Metal,
Liquids: Snow, Ice, Lava, Water,
Gases: Fire, Eletric Air, Sound,
There is more then this out there but these are the general I see in RPs. Solids give x2 damage to Gases but take x2 damage Liquids. Liquids give x2 damage to Solids but take x2 damage from Gases. Gases give x2 damage to Liquids but take x2 damage from Solids.
With this said if you want to flip said consequence just contact admin where you will say "Instead of the usually taking x2 damage from ____ I will take x2 damage from _____." and "Instead of causing x2 damage to _______ I want to cause x2 damage to _____ instead" Please be descriptive. Making a character sheet can be the hardest part in a game.
tbh You could use the pokemon typings for strengths and weaknesses, especially if you are giving people a lot of liberty with their elements. It would need a little reworking, since 'fighting' and 'fairy' are not elements, but at least it is already fairly balanced and logical.
(also snow and ice are the same thing, just putting that out there lol)