Thank you! The art is done by our amazing friend Yui Maehara (nyuma.art)
About the dices, the silver and golden dices are indeed better, the silver are fixed on a specific roll so you can get a silver dice with only 1, 2 or 3 this one are the ones you'll use more strategically to position yourself (now there's a reality in our game and is that the RNG can really beat you up, more so in the beggining of the game)
The golden dices only roll 6 so are really good to use to break the gate or in a tough situation combat it's even useful to position yourself in a good spot but this is more situational because they will break with 1 use
That's why is a good move to use the mystery events to pull off silver dices to get more options instead of leaving all to RNGesus with the bronze dices
With all these said the game does have a lot of rng, so i totally understand your frustration, thanks again for playing our game!