"No Defenses Set" in Grand Arena [MERGE]

The same garbage happened to me too. Why join and then not even bother to set Defense? Don't want the other guy to have to even work at all? It's selfish and IMO will be the biggest problem with this game mode, as it completely drains the fun out of it. I was excited to battle and now I'm just angry and exasperated.

There needs to be some way to avoid this. Some kind of penalty to players that intentionally don't set Defense.