From the Tyranid Codex -
Absorb Life: The Doom of Malan'tai immediately gains +1 Wound, to a maximum of 10 Wounds, for every unsaved wound it inflicts.
It doesn't matter if it's a psychic ability, Spirit Leech, or close combat.
I don't know why more people don't take him for the 130 points it costs for him and a Mycetic Spore, unless you only face can spam.
And thank you for the compliment!