Spell of Revelation

The Spell of Revelation is an enchantment with which the true nature of one thing may be revealed. The Spell of Revelation - "Hierste þæt íecen sóna" - is powerful magic, but it applies only to objects, things, not to living creatures. Anyway, Merlin tried this spell on the troll Catrina to reveal her true form in front of the entire court of Camelot. Trolls' magic was so powerful that Catrina resisted to the spell, even though she felt it and had to take her potion again (Beauty and the Beast: Part Two).