>>718401816
Pyramid spawning or their drops are not rng. The vertical meter tells you when the next pyramid will spawn. Killing lots of enemies fills it faster. When pyramid appears it starts dropping but stops when you kill a pyramid so the faster you kill the pyramid the higher the meter will stay so the faster will the next pyramid spawn.
That's why having high dps for killing pyramids and as wide shot as possible to hit all enemies on screen at all times is my meta and Shinto on Marisa fills both criteria excellently