Lifeforce Reservoir (M2, P2)

Level4

You siphon part of your lifeforce into an unseen reservoir. When you cast this spell, roll @[2d8][roll 2d8 as damage for 'Lifeforce Reservior'] and reduce your current and maximum Hit Point totals by the result. As a reaction or swift action, you can channel the reserved lifeforce into a dying creature within 30 feet of you, restoring @[4d8][roll 4d8 as heal for 'Lifeforce Reservoir'] of the target’s Hit Points. If you use this effect or it expires, restore your maximum Hit Point total to their prior value.