Pyromancer Boss power

Does anyone know the rythym/activation of the downwards fireballs? I keep running into them because I can’t figure out what activates them and makes them come down.
If I knew when they were falling, I could avoid them more easily.

All of those types of powers will activate on a certain timer. It’s very regular. The timer will reset when the opponent is knocked down. The projectiles will also always show up in the same relative spot on the screen. It also depends on what level of power they have. For example, a low level pyromancer will have an arrow shoot down at the center of the screen. A high level pyromancer will have an arrow shoot down 1/3 of the screen and 2/3 of the screen.

Note: this does not apply to the stone power

These drop down powers are the worst for Arg! xD