Thank you :)
The UI definitely is a headache even without thinking of controller support, but luckily once you make a few basic working menus it easy to at least produce a working UI. The trickiest part for me is UI Design and making it look good, That's a struggle.
And as for G.A.S (if u mean the "Gameplay Ability System") I actually have never touched it but have heard of it. For this project it was mainly creating and wrangling custom blueprints and nodes to get the project to work. But I'm happy with the result. Thanks for checking it out :).