New player asking for advice :>

Here are all the fighters I own! :D I was wondering, are the three gold characters that I have good? I've been investing in them in terms of XP and some skills, didn't use any keys tho :>

I'd appreciate any feedback and advice on how to improve and who to invest in!

For the main chapters of the story, I've completed all of them on Advanced difficulty, with the first and third one also on Expert difficulty :]