RPG skill system like KH recoded

I want to create a skill system like in Kingdom Hearts recoded where you can equip multiple skills and when you press a button it performs a skill and when you press it again it uses the next skill. How can I do this?,I want to my character able to transform only when certain conditions are meet like when he takes enough damage/ when enough time has passed in battle etc. How do I do this?

That’s a pretty big question. And something that’s gonna take as long to explain as to make.

Suggest you check out this guy:

He has a guide for creating ability/skill system with talent trees, draggable skills to an action bar etc.

Now as for making the skills transform into something else that’s fairly simple in itself. Just update the icon (with an animation if you’d like), maybe change the tooltip and then just have the same skill perform a different effect on the second click. Maybe add a timer saying that if it isn’t clicked in x seconds it goes back to the first one again.