This arena is very bugged.

If you have any ninja in first position, sometimes do not use the mystery first, but 3th or 4th or even after all the standard attacks of the other ninja. Root of warrior of the light main sometimes does not work and in the first round i have any debuff on me. It is not immune to anything. And often the matchmaking timer goes on for minutes and if you try to cancel, a message warns you that you've already found opponents, forcing you to reload :/