Last levels in Events

[allwind]

I often find the last level in events very frustrating. So frustrating I sometimes

feel like I want to destroy my smartphone. It took me a long time to get a 4k Team Power. It is a big frustration flunking on last levels in events. Despite using Max of expensive battle items with the required team power. Especially when one failed try easy can take 15 minutes.

This time it was last Santa level. I made it to the last 3 bosses, without using much of my battle items. However, how hard the bosses hit when they trigger is way too hard. They will almost immediately kill my healers.