Reproduction Steps: 1. Deploy Frostwing Glaive. 2. Use Arcblade: Frost. 3. Let the enemy hit you 2 times. 4. Your Arcblade will be available at the beginning of your turn even though the ability doesn't say its CD goes down. @Sokolov
Just found out this applies to Arcblade: Electricity as well. I believe all the arcblades are affected.