Medea: In point of fact, my knowledge does not amount to much. (36)
Medea plays down her knowledge in an attempt to seem less threatening to Creon. The king, however, doesn't buy this argument at first. Medea's skills are well known, as is her cunning.
Creon: You are dangerous. All your cleverness shall not keep you here. (37)
It's amazing that Creon is so aware of Medea's craftiness yet he still allows her to stay in Athens for a day. This could be seen as some rather dubious plotting on the part of Euripides. His plays have often been accused of having sub-par plots, causing some scholars to place him below his contemporary, Sophocles.
Medea: Plot, Medea, devise you recipes: advance to the deadly act that tests your courage. (57)
Much like modern superheroes, tragic heroes and heroines are usually extraordinary in some way. Medea's "super power" is her intelligence and skills at witchcraft. When she is threatened, she turns to these abilities for protection.