Ice Make: Diamond Cage is an Ice-Make Spell.
The user creates a diamond-esque sphere of unmeltable ice on the target's body. It was stated that this spell destroys the body of the person trapped inside, along with the ice itself. However, the sphere loses its hardness the farther away it gets from the caster, until it eventually shatters. This spell was only named in the anime.
- Fairy Tail Manga: Chapter 29, Pages 11-12
- Fairy Tail Anime: Episode 12