This skill, at least at level I, is bugged. Rather than reduce the magicka for the next spell cast it limits the amount of self-healing for that period. EG. if Rapid Regeneration is ticking (say 79 per tick) and then symmetry is cast, the amount of the healing drops from 79 to 4 for my character. The primary reason for a Templar to use this spell would be to negate some of the huge cost of rushed ceremoney. However, when rushed ceremony is cast immediately following spell symmetry it heals for 28 instead of 571 (norm).
WTF?