I Wanna be the Simple - Blue Fire, Final Boss

Spent more than 2 hours yesterday to understand how survive 8th hit and failed it; manage to finally survive it by miracle and then first try last two hits today within 2 minutes of attempts. Sounds reasonable. Kinda fun boss, but man it's hard and every attempt drains so much energy
took 3 hours overall or so
Difficulty - 72/100
Enjoyment - 5/10