Hashashin is currently broken in arena and the root of the problem is specifically with its eye of the storm skill which has such a long super armor on top of a low cooldown applied in arena. In fact it can be used up to x24 times in 1 minute which amounts to ~48 seconds of immunity and with some dodges, sandstorm slash & mirage abilities involved this easily adds up to 1 FULL minute of immunity. In other words, a hashashin who figured how to chain his immunities is unstoppable.

While hashashin's rotation is acceptable in field pvp because it's normal for all classes to remain in extended immunity state in mass pvp, it's absurd how hashashin still gets to remain in a crazy long immunity state in arena when there are classes like destroyer with super armor skills that are super short once applied in arena. For all those reasons hashashin shouldn't have any immunity applied on the second charge of eye of the storm in arena, or should receive any other sort of adjustment, this way hashashins will have to think twice before using their skills instead of spamming eye of the storm nonstop without any drawback as shown in this video: