The Pokemon TCG loves to pay homage to the holidays, especially the spooky-themed Halloween season, through subsets like the Trick-or-Trade collection
The ten less damage isn't a lot, but when added to Skarmory ex's Steel Wing, that's 40 less damage every turn it attacks since the tool stays unless the Pokmon is KO'd or Guzma takes it off
Top of the pile, however, is Toph, the First Metalbender
This idea of using subtypes as a means to add mechanical identity has proven useful and has become a valuable tool in building sets
Otherwise, this card could see competitive play, but Virtue of Knowledge really is tuned for the Commander format first and foremost
We have to keep in mind what kinds of requirement ritual-focused combo decks are good at meeting