Arcane Barrier II

You create a Magical Barrier that absorbs damage until it breaks. 

The barrier has HP equal to 15 + your Focus. The barrier has a Guard of 0 + your guard and any damage it takes is subtracted from the barrier’s HP. When the barrier breaks, any remaining damage is subtracted from your HP. The barrier otherwise lasts until the start of your next turn or until you take any action other than the Block action. If using the Block action while the barrier is active, the guard of the barrier also increases. 

This spell does not provoke attacks of opportunity and does not protect against true damage.