Vahn's Dubious Deflector

The caster throws his hands up and a 10ft square panel of magical force originating from the caster's palm appears to try and redirect harmful energy. If the panel is cast in an area smaller than a 10ft square (such as a doorway) the spell fills the available area but does not continue into the groundThe panel has an AC of 20, resistance to all damage except force and 20hp. Any attack roll made at a creature behind this panel must first target the panel, any damage in excess of the panel's hp will affect the original target. Spells or effects causing an instantaneous damaging area of effect (such as a fireball, ice storm, or a dragon's breath attack) can be blocked by this panel, even if the spell specifies it travels around corners, but if the damage exceeds the panel's hp then further damage will still affect the original target(s). Any effect that could destroy a Wall of Force completely bypass and destroy this spell. This panel dissipates at the beginning of the caster's next turn.

At higher levels: For every spell slot higher than 2nd the panel gains +2AC and +5hp. For every 2 spell slots above 2nd the panel also grows by an additional 10ft per side (20ft square at 4th, 30ft square at 6th, 40ft square at 8th)