Originally Posted by Taon

Some of the events we get are referred to as "Raid Boss events"; simply put the event currency and other rewards are earned by summoning special Raid Boss monsters and/or assisting to kill other summoned Raid Bosses. The most recent one we had was back in. These Raid Bosses are massively tough and hit pretty hard and each team of girls is limited to 5 rounds of combat before a draw is declared and combat either continues with the next team, or combat ends if there are no more teams. Because you can only fight these bosses with your Raid Points, you really need to maximize your contribution and ideally not have to spend multiple points to ensure that the boss will be defeated before it flees at the end of its 2-hour window.

That's where x% damage against Raid Bosses comes in handy and it makes a tremendous difference. Otherwise it also works on the raid bosses that occasionally pop up after missions, but it's generally overkill there.

Oh thank you for reminding me, I actually forgot about the Raid Boss Events. But I never had problems with those. In fact, my only concern was to attack the boss before the players nuked it and I get the message "The Raid Boss has already been defeated."
I actually didn't even use a full squad on these events to help me fight the bosses more often. I never looked foward for a girl with raid boss % atk increase and I'd rather have an ability that's helpful all the time instead of in a specific event.