Low Damage in Story Mission

I do not understand why in higher level (Chapter 4) dungeons something like a 2 star sparkgeist can take 6 ultra element (all) attacks. Why am I doing so little damage < 400? 

I do not understand why in higher level (Chapter 4) dungeons something like a 2 star sparkgeist can take 6 ultra element (all) attacks. Why am I doing so little damage < 400? 

To make the game harder they buff the mons, it’s not their actual stats. The further you get the stronger they will get.

Okay, at least I know what I am getting into now. Thank you!

Chapter 5 has the most buffed monsters and then Chapter 6 has monsters with normal stats but larger teams

Im having difficulties at fire temple chap 4.
The rest of chap is piece a cake

I thought chapter 4 was the hardest one. I breezed thru 5 and 6.