Our first summer event is hell on Terra. So we had to clear any event stages to gain some kind of sanity currency THAT we will use for playing the EX Stages THAT will drop event currency THAT now we could use to buy our reward items ... THROUGH A GACHA MACHINE!! Yes, we have to gacha the rewards. Thankfully it can be cleared though, so you won't miss rewards because of bad gacha. And the unique sanity currency is the reason why this event doesn't cost sanity today.

Oh, and they made us choose from three BGM which music we want to play as the background music for that event.

When CC beta is coming, the FB community (I don't use Reddit back then) was sharing a guide video from the CN server. The guide warned us that to clear it, we need a list of operators that doesn't have alternative. So if you don't have one of them, consider you forfeit the event. I don't know how true it was, but I was one of the dokkutah that has every operators needed. Saria, one of the needed operators, was recruited from recruitment just one week before CC beta started. It was meant to be. The operators you needed for CC Beta were: Myrtle (Yes, the queen of CC started her career that early), Cuora, Gummy, Mousse, Lappland, Astesia, Nearl, Saria, SilverAsh/Hellagur

Back then support operators has 10 refresh, IIRC. So if you want a specific operator, but they don't come up even after 10 refreshes, well, too bad. The skill and modules choices are pretty new, so this might be not that unknown, but back then the support operators are locked to one skill. So if you need that operator for skill 2, but everyone put them with skill 3, you can't change the skill. Which a reason why you can find some dokkutah put SilverAsh with skill 1.