As a reaction, you can cause a close burst 3, pushing enemies outside of the radius, then erecting a dome-shaped shield in a 3 square radius, which absorbs all damage to a limit equal to 200% of a heavy damage roll, and blocks all movement and line of effect until taken down.
Feats
Regenerating Shield: your shield's max HP increase by 100%. It regenerates 25% of its maximum on your turn start, assuming it hasn't been reduced to 0. Otherwise, it must spend an entire turn regenerating to 1 HP, then it can regenerate normally.
Force Capacitor: all damage you absorb with your force shields can be tallied. Any time you make a physical attack, you can add the tallied amount to your damage as force damage, depleting it. Tallied damage is lost at the end of the encounter if not used.