Your search for "Blade Knight STP4-EN017" revealed the following:
Blade Knight - CT1-EN002 - Secret Rare - Limited Edition from Collectible Tins 2004, available at 401 Games Canada. Rarity: Secret Rare Card Text:If you have 1 or less cards in your hand, the ATK of this card on the...
Blade Knight - STP4-EN017 - Common from Speed Duel Tournament Pack 4, available at 401 Games Canada. Rarity: Common Card Text:Gains 400 ATK while you have 1 or less cards in your hand. If you control no other monsters, the...
Blade Knight - SBAD-EN006 - Ultra Rare - 1st Edition from Speed Duel: Attack from the Deep 1st Edition, available at 401 Games Canada. Rarity: Ultra Rare Card Text:Gains 400 ATK while you have 1 or less cards in your...