Advanced format ruling
Arcana Knight Joker
Card effect (current official text)"Queen's Knight" + "Jack's Knight" + "King's Knight"
A Fusion Summon of this card can only be done with the above materials. Once per turn, when a Spell/Trap Card, or monster effect, is activated that targets this face-up card on the field (Quick Effect): You can discard the same type of card (Monster, Spell, or Trap); negate the effect.
Current rulings for this card are maintained by Konami.
Rulings data courtesy of Format Library — formatlibrary.com. Spotted an inaccuracy? Flag it in the Advanced forum — sourced change requests get reviewed.