How can a Muse 'command' by being the most passive class in all Homestuck?

Because ‘Passive’ and ‘Active’, even with the Master Classes, seem to refer more to the Intent behind using your powers rather than whether you’re directly doing something or passively influencing it. Lord English’ Alpha Timeline is so incredibly Passive, but it only benefits him. Calliope’s Rapture is an incredibly active and deliberate act, but it’s done as a ‘For the Greater Good’ finale.