This powerup will allow you to walk through enemies and walls for a period of time. Includes: the patch itself, a sprite, and a block. I think I tested it pretty well, so I hope it doesn't get rejected for that reason. Video. Ignore the status bar and one hit kill in the video.
Conversion works well and behaves as it should, so it's accepted. The only thing of note is if you want to use freeram not in the direct page ($7E00xx), and you're on SA-1. If you need it to be somewhere else (absolute addressing), append "|!addr" to all of the freeram definitions. For example, "!FreeRam = $18CC|!addr".