Crystal Beast Effects(S/T Rulings)

I have a question regarding to the Crystal Beast Effects. Let's say I have Emerald Tortoise at the S/T Zone. I Normal Summon Amethyst Cat and attack directly by effect. Can I still use the Tortoise's effect to change the Cat to Defense?

Crystal Beasts do not have their effects while being Continuous Spell Cards.

No, Emerald Tortoise is treated as a Contuous spell and loses any effect that it would have while it is a monster.

Thanks, everybody. I feel so much better now.