Edit2: Belphomet, Worldreaver cannot be destroyed or banished by card effects such as Nature Corroded. Some cards are too strong and it makes it frustrating to play such as Karyl, Catty Sorceress has the most ridiculous effect, it reduces the maximum defense (health) of the enemy leader by 5 points, more frustrating with the Union Burst and if the other player plays 1 Karyl each turn. EDIT: With the latest update, after 2 tries, it works on my phone too.