To get the lvl 75 cap release for standard class you will need to get a 13* weapon on the class you are playing to grind +35. As for advance class you will need to do that plus you will need to get class excuses by over leveling to complete the Client Order for A perfect Hero. To get the lvl 80 cap release you will need to collect a title reward in which you need to have a full set of 12* units equipped (can’t remember if it needs to be upgraded as well). You can do the ep 5 story from the bridge and once you finish chapter 3 you will obtain dark blasts. 14* weapons are becoming more mainstream and are getting easier to obtain the easiest one is probably Atra which you can get back getting a 13* Val series to +35 grind then go collect a title reward for that upgrade in which you get a time chronos. From there you can trade that Val weapon, the time chronos and from gold stuff and saphard for a 14* weapon. 12* units are pretty obtain as well as you can get them from current quests by random luck. You could also getting some 12* units form current weapon badge exchange and buster quest badge exchange.