You designate one creature within range as your soul feast target. Each time that target takes damage from you or an undead minion you control, it leaves behind a fragment of lingering soul essence. At the end of your turn, you may consume these fragments, choosing one effect for each:   Regain 2d8 hit points per fragment.   Empower your next melee weapon attack to deal an extra 3d10 necrotic damage.   Regain 1 expended rune per 2 fragments consumed.   If the marked target dies while under the spell, you may consume its entire soul essence, gaining all three effects immediately.