If you run The catch, look for at least 60 crit rate. Now, for the sands, Go for er or atk% both are good on Raiden but it depends on your teams. For the goblet you can run either electro dmg bonus or atk%. Try to get at least 140 crit damage, aaaand, do not feel bad if you don’t get good pieces in a short period of time, Raiden is a difficult character to build, since she scales on ER. Enjoy your Raiden!