Just set the bullet sprite frames lets call frames (f)
On normal set bullet to shoot f0 on power up 1 set bullet spire to show f1
So voor every power up you have you can get a diffrent bullet
So on pick up power up
Set bullet frame to bullet you whant also you can edit the dmg and speed diffrent voor each power up pick up.
Its easy to do in your event sheet and also on your bullet sprite
Just first add all different bullets to your bullet sprite set them in the frame every frame 1 bullet
And write witch one is on witch frame then make 1event in your event sheet copy paste it So if you have on bullets so 9 bullets 9 events total and then edit the power up objects and the bullet frames and if you have dmg and speed settings you can edit them to and your done easy i think its faster done then writhing this poste 😀
Hope that helps you