Both combatants can fly, Psychoshy really doesn't have any ranged options, I imagine she has some experience dodging gunfire, but in all honesty.
I think Bug Stickman will blast the hell out of Psychoshy and she would have to prioritize dodging and trying to close a gap that she wouldn't be able to avoid the danmaku of poison with the vines that will certainly restrain her...
I have to give this to Bug Stickman for being able to lock her down, force her to play aggressively, and even though she can have homing attacks and her
Pipbuck gives her warmings of terrain, she has to take risks here if she wants to beat But Stickman which will leave her vulnerable.
The only thing I can think of that would make this null is if her Biological Manipulation resistance applies to poison as well, because if that is the cause this changes my argument.