Uhh, Kaeru, Osu is made to test your "surviving" from the music with the selected mods, not to "attack" other player game with mods, right? With your brand new ideas, everyone might not be happy when play because of the power-up effect. If me, i said that your ideas could make someone stressed. And with your ideas, the game needing a luck. Which means, this is not happy-to-play mode. Rather like fight-to-win.
But fine, i will give you some request. Make it so the power-up could be saved and turned on to other player with Spacebar when he/she wants to affect other player game at the time.
I won't vote (Or maybe dislike, if there is)
*sorry if you don't know what i mean beacuse of my language.