Tears of Ilmater

"Cry for those who suffer, and take their pain unto yourself..." 

Once per round, as a reaction, the cleric can choose to take the damage inflicted upon a friendly creature within sight unto themselves. If this is used to prevent the friendly creature's loss of consciousness, the cleric heals for 1d8 points of health. If this prevents the friendly creature's full death and the cleric is both alive and conscious, the cleric heals for 2d10 points of health. 

When used with higher level spell slots, multiply the amount of dice by that spell slot minus two (ex. 3rd level, minus 2, multiply by 1).