Advanced format ruling
Tethys, Goddess of Light
Card effect (current official text)When you draw a Fairy monster(s) (except during the Damage Step): You can reveal 1 of those monsters; draw 1 card. This card must be face-up on the field to activate and to resolve this 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.