Lugia

Lugia possesses some of the greatest bulk in the metagame backed up by one of the best defensive abilities in Multiscale. Its access to reliable recovery, a great Speed tier, and an extensive support movepool ensures that it can keep itself healthy with relative ease and effectively check various threats such as Zygarde, Groudon, and Rayquaza. Its walling capabilities, however, are entirely dependent on Multiscale, which makes Lugia very hard to utilize considering it must be kept at full health or else risk being taken down by the multitude of fast and strong wallbreakers in the metagame. Lugia also despises all status ailments and must avoid them at all costs, making cleric support with Lugia important and making it a natural fit on stall teams. While Heavy-Duty Boots is a godsend to rid Lugia of its weakness to Stealth Rock, it also means it lacks passive recovery and can't switch in on certain Pokemon it would otherwise beat, such as Landorus, in fear of Knock Off. Lugia's defensive typing also leaves much to be desired, giving it weaknesses to the extremely common Ghost- and Dark-type attacks. It also cannot deal with the best offensive and defensive threats in the metagame, being completely outclassed by Necrozma-DM and Lunala, both of which share Lugia's Psychic-type but have a much better secondary typing in Steel and Ghost, respectively. On more dedicated stall builds, Giratina is bulkier and can provide more for its team.