Complex sentence: She has remained a mainstay with her team until D'Gard was made leader and they faced hate mongers, she remains with them till now and it is unknown if she lost or retained her powers after M-Day.
Split into simpler sentences: She has remained a mainstay with her team until D'Gard was made leader and they faced hate mongers. She remains with them until now, and it is unknown if she lost or retained her powers after M-Day.