Unless the spell or ability targeting Phantasmal Shieldback has one or more other targets, it will then be removed from the stack when it tries to resolve. None of its effects will happen.
When this creature becomes the target of a spell or ability, sacrifice it.
When this creature dies, draw a card.
Phantasmal Shieldback's first ability resolves before the spell or ability that caused it to trigger. It resolves even if that spell or ability is countered or otherwise leaves the stack.
