The Celestial Alacrity Specter build for Guild Wars 2 is a versatile Thief specialization designed for raids. It offers strong boon uptime, including Alacrity, Might, Fury, and Protection, while maintaining solid healing and support. This build is ideal for replacing a healer slot in most groups, providing crowd control and barrier generation alongside its offensive capabilities. However, it requires resource management and careful execution to maximize effectiveness.