Hi, I think walking wave is not so good. Because of its self hurting attack it is an easy target to get easily beeing knockout. And what you think about the new ass card secret box? It let you discard ancient cards to increase the ancient number damage and let you search many needed cards.
Why most players use Walking Wake bc is his retreat cost of just 1, and he is also an Ancient Pokémon. For me, I still prefer Awakening Drum over Secret Box. Card draws is always better. Just my opinion Also, usually u will not use Walking Wake to attack