@Doenyon The trance magic was mentioned when god visited her cafe back at 5 or 6? If you're a bit lazy to reread it, if I got it right, saviors are granted tremendous amounts of MP upon being world hopped but they need to constantly release their MP. In spoiled saviors case, since she hasn't learned a single spell (plus the power up she asked god is "to be beautiful"), then all her excess mana is leaked out and sadly makes the poor prince its victim (as what he mentions this chapter, he has trouble saying no to her)
Edit: The specific page where trance magic was mentioned is on Ch.06 pages 6 and 7