Tacho's Crystal Shield

A large crystal casing forms around the caster. This gives them temp health equivalent to 5 times the spell level used. When this spell is up the casters movement speed is treated as if it were difficult terrain. Flying speed when this spell is up is reduced to 0ft. When the shield's hp is reduced to zero the creatures within 10ft are subjected to a dex save vs d6 magical piercing damage equivalent to the level of the spell.

If they succeed then they take half as much damage, failing takes full.

"When the kobold's of Thunder Guard's entrance to the under dark first learned of the crystal cavern below they thought that they had immense wealth. The court sorcerer realized they had immense power."

~Talbot Grimes