Well first i used the lag to practice and see what will happen first, but it will not be only thing i have to focus on. I also have to focus on the main boss, The Yatagarasu.
I saw the video and it looked easy but when you go to the great thief's world (aka The Yatagarasu) he transforms into mega Rayquaza and his attacks have better speed. So you have to be careful when you get to his world.
Tbh, only me, and two of my friends made it to 12% on The Yatagarasu. obviously because we had enough concentration, but the one thing we missed was the good timing to tap on the screen to jump, and pass the obstacle...