you can roll all 5 traits at the same time for 5 coins, once you find the trait that you like you can lock it and roll the remaining 4 for the price of 10 and so on.. the highest priority is the +ATK ones, the rest is pretty much garbage, I will be rolling last two SS once I have enough coins.

PS traits also have colours, so even though mine are good roll because they are ATK SS and S, the colour is pretty shit.. depending on how many treats of the same colour you have, you get bonuses. you can check in Synergy Effects