when a creature attacks and ally within 30ft, you encompasses your ally in shimmering magical energy (players choice what it can look like) if the creature hits the ally, the creatures must then make a constitution saving throw against your save DC. On a fail the ally deducts 2d8 + Intelligence from the damage roll as the attacker becomes disorientated, if the creature succeeds the save the ally only benefits from half 2d8 +  Intelligence.  

For every level this spell is cast above 3rd add 1d8 to the roll