[ Well, that sure was ugly and repulsive. But Noctis mentioned weakness to a type of element...? Typical video game fare, heh. Based on the elemental interaction chart from earlier, its color... ]

Blue... It could signify either ice or water.

[ How impractical that both ice and water used the same element. ]

Should it be the former, then it is weak to fire. If the later, then lightning should be its weakness.

[ ... And she has access to neither. Well, she'll use Dark Savior anyway to try and deal some damage. ]