We were speaking about CT. Janus is more powerful than Schala at the beginning, Magus is more powerful than Schala during the game, and Magus is more powerful than Schala in CC (if he's still alive). After CC, Magus is most probably still more powerful than her because there's no evidence towards the contrary. Schala could obviously beat him at a philosophy contest, but Magus could still nuke her regardless of her knowledge about the meaning of life.
Even if Magus is powerful, Schala still has techniques to own him. Firstly, she can't die because of her pendant. Secondly, we know that she can errect barriers on things, so she could just trap him in a cage. Thirdly, Magus lost energy to Lavos.
And the fact that Janus only hides a magical power that surpasses Schala doesn't mean that he surpasses her in every aspect. He probably has far greater shadow magic than her, and that is why later we realise that he could time travel and fly. Schala, on the other hand through CC is shown to be much stronger. If one second of contact with a Lavos that is draining your energy makes you loose like half of it (Magus), then what about 13,000 years for Schala? Even while in contact with him, she managed to create Kid.
Later on, she can time travel and cross dimensions without being a missing piece. Plus, RD does make her even more special, by revealing that she is an arbiter.
And yes, I do like Magus. But Schala clearly pwns him.