Roll With It

Momentum Power
At-Will (once per round)
Action: 
Interrupt action; requires momentum
Trigger: 
A melee attack that targets AC hits you.
Effect: 

You take half damage from that attack.

Adventurer Feat: 

The power also triggers on an attack against PD.

Champion Feat: 

The power also triggers on a ranged attack.

Epic Feat: 

Once per day, you can use roll with it to take damage equal to the attacker's level instead of half damage.