>>44527273It calls itself 'casual' mode because it's relatively easy compared to the other 2 modes, not because it's easy. This is the 5th gym leader's team, keep in mind that on her 'field' Swift Swim is always active, ground type moves don't work, and water moves are given a large boost in power.
Reborn doesn't have an 'easy' mode until the next update.
Both Reborn and Rejuvenation's Normal Mode are beatable without dedicated EV training/nature shit, it's just really, really hard.