That's true. I was thinking about it for use with one of your sengir vampires. You could mage it up some more instead of adding more lifelinks.

I hadn't thought about that, although, consider alabaster mage and child of night.  I kinda see Angel's Mercy as absorbing a heavy blow.

Have you considered trading your angel's mercy's for a couple Lifelinks? Lifelink is a one drop compared to a four drop and depending on how you use it, you can get more than 7 life from it.