Advanced format ruling
Guardian Kay'est
Card effect (current official text)Cannot be Summoned unless you control a face-up "Rod of Silence - Kay'est". This card is unaffected by Spell effects and cannot be targeted for attacks, but does not prevent your opponent from attacking you directly.
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.