Once per turn, during either player's turn, when your opponent activates a Spell/Trap Card: You can negate the activation and destroy it, and if you do, this card gains 500 ATK until the End Phase
Challenger +2 grants Captain Hook, Forceful Duelist an extra two points of strength when he challenges opposing characters, making his effective strength three when taking the fight to your opponent
This means that if you KO an EX with Plasma Gale, you can take 3 Prizes, which can end a game very quickly
Its only gotten stronger over the years, with cards like Generous Ent to help smooth out the mana and keep the deck consistent
For the extra curious out there, 1pt is equal to 0.001" or 0.0254mm - confusing, we know
You can only use each effect of "Joker's Wild" once per turn