>>32539938>>32539964Guzzlord=Gluttony because duh.
Pheromosa=Lust, due to pheromones (inb4 "just because you're beautiful it doesn't mean you're lustful". She isn't lustful, she instills lust)
Xurkitree=Greed, as it raids power plants to absorb their electricity
Buzzwole and Kartana=Pride and Wrath, or viceversa. While Buzzwole looks like a bodybuilder and Kartana is a literal katana (remember stories about Muramasa's blood-seeking blades?), their concept arts with Buzzwole wrestling with Pangoro and Kartana acting like an old-fashioned samurai could make it appear this way as well.
Celesteela=Sloth, being the heaviest Pokémon which also gets its nutriment from the soil in a tree-like fashion. And being based on Princess Kaguya, who used to stay at home during her youth, sheltered by her adoptive parents.
Nihilego: Envy. This could be a reference to either Lusamine's obsession with UBs or its codename, which in the Japanese version is flat out "Parasite", reflecting the "mindless" (Nihil ego=No ego, like the conscious part of the psyche) and parasitic behaviour of an envious person, who establishes his or her existence as "having to be better than someone else".
I don't find it forced and, while certainly it wasn't the principal idea in their design, it might have helped GF's creative process.