[LV1][LV2] While there is Soul Core on this Spirit, this Spirit cannot attack, and is unaffected by opposing effects.
[LV1][LV2] (Every Main Step) When a player activates an effect that increases core from the void, the core is taken from the life of the player that activated the effect instead of the void. Neither player can activate a burst if the life is reduced due to this effect.
Rulings:
Ruling: This Spirit cannot affect the cores obtained from Core Charge, but they can affect cores a Grandwalker Nexus puts in other places (Cards on the field, Reserve and such).