What is Vullfy's role in PvP ?
Vulffy is a solid pivot thanks to its high special defense, excellent defensive typing, and access to recovery through Lifeful Sap. Its Team Elusive trait and access to Jinxed Whisper also makes it able to avoid a lot of moves during a match, making it pretty hard to catch and KO. Plague also loads Vulffy with utility, allowing it to trap opponents with Handcuffs and cripple the opponent's Stamina with on-demand exhausts.
What kind of teams appreciate Vulffy ?
This particular set takes a bulky approach to playing Vulffy. The build makes Vulffy particularly good in mid-range and stall-oriented teams that can afford to run Kinu or other Stone Wall users to stack defensive boosts on it. Having another earth type is also great, because it allows for Bush to also become a defensive setup tool, but that is easier said than done as there aren't plenty of great earth types currently. Other Bush users also like being with Vulffy for the same reason.
What is the best way to play Vulffy ?
Vulffy can be a decent lead, especially alongside Kinu, as it can use its resistances to wall electric and crystal types while threatening earth and water types with Plague. Its resistances and Team Elusive also make it able to pivot into many moves. When on the field, you can either use Lifeful Sap into a switch out, take decent trades with Plague's Exhaust and priority, or hit crystal, electric and fire types with Dust Vortex.
What is the goal of this specific build ?
This set aims to maximize Lifeful Sap and Revitalize recovery, and gives Vulffy balanced bulk through a high defense investment.
The stamina investment on this set ensures Vulffy can use Plague three times in a row without overexerting, thanks to Sweatband. A small Speed investment is also run so Vulffy can outspeed the slower end of the priority 2 metagame with Jinxed Whisper, namely Zaobian.
Leftover TVs are dumped into Special Attack, allowing Vulffy to KO most Temtem that are weak to Plague in two or three hits. It also secures a KO on Half-full Scaravolt at +2 Special Defense, as long as they don't have a huge Special Defense investment.
While most Vulffy sets would run Handcuffs for the obvious Plague traping synergy, this set runs Sweatband instead, granting vulffy great staying power when combined with its Lifeful Sap regen and stalling capabilities through Jinxed Whisper.
What can actually deal with Vulffy ?
Melee moves are an obvious way to deal with Vulffy as it's its only weakness. Banning Kinu is also an option, as Vulffy quickly snowballs out of control if it gets its defenses boosted. Without defensive boosts, despite having a good chunk of defense investment, strong double-ups from physical attackers can threaten Vulffy.