The ability doesn’t change how much damage is dealt; it just changes how much life that damage makes you lose. An effect such as Spirit Link will see the full amount of damage being dealt.
Sustaining Spirit
If an effect asks you to pay life, you can’t pay more life than you have.
Paying cumulative upkeep is always optional. If it’s not paid, the permanent with cumulative upkeep is sacrificed. Partial payments of the total cumulative upkeep cost can’t be made. For example, if a permanent with “cumulative upkeep {1}” has three age counters on it when its cumulative upkeep ability triggers, it gets another age counter and then its controller chooses to either pay {4} or sacrifice the permanent.
Magic: The Gathering · ™ & © Wizards of the Coast · Illus. Rebecca Guay
Card data via Scryfall. Rarix is fan-made; not endorsed by the rights holders.
