I used to joke that every single sideboard I played had at least one Needle in it when I started playing Legacy
Byway Barterer Byway Barterer looks like a powerful enabler for prowess decks, refilling your hand with a bunch of cheap spells each turn when you expend 4
Even static lock effects can draw widespread applause for interesting gameplay, when theyre of the softer, taxing variety, a la Thalia, Guardian of Thraben or Kambal, Consul of Allocation
They can do just fine steamrolling you without it
03 Galaxy Foil and 1013 Traditional Foil cards
Mankey and Primeape together are also some of the best Pokmon to have while going second, meaning you likely do not need Regirock as a wall for this list, and can instead run Marshadow for a possible 140 Revenge attack