I think that how these "dilemmas" manifest is just a reflection of the relevant character's belief/misconception of what happiness is. Pieta was stuck in a time loop because she was, for a time, convinced that clinging onto momentary happiness was ideal. Nike's likely has to deal with power and how having power allows her to obtain happiness, which lines up with the witch saying that only those who have power can take happiness from others.
I feel that the reaction to magical abilities being shounen is a bit kneejerk, and if there's anything truly shounen so far, it's the potential that Nike will find a resolution through the power of friendship, as that was what allowed Pieta to get over her dilemma.