If you read the opening page on this Official Fan Website, then you already know the Shadow Queen asks for personal service rather than cash to become a member of her legions, much less one of her personal minions. Membership; however, is quite easy to manage as a simple TeenyBorg Legionairy who just have to show up and tell at least one person on the planet they liked what they found here.
(although in her case, it's more likely you will be honored with a position at the research labs,
as a test subject of course - look on the bright side, just think of all the neat things you can try with all those extra limbs and eyes she likes to install!).