This delightful sequence turns a humble wall into an engine of endless vitality. By using Agatha's Soul Cauldron to exile Spike Feeder, you grant its activated ability—removing a +1/+1 counter to gain 2 life—to any creature you control carrying a +1/+1 counter. Wall of Limbs is uniquely positioned to capitalize on this, because every time you gain life from that borrowed ability, its own static text triggers to put a +1/+1 counter right back on the Wall. That newly replaced counter can then be removed immediately to gain 2 life once more, creating a self-sustaining loop of infinite lifegain and lifegain triggers.