I havent done this instance yet, but through what u said the clone keep using planetary devastation to destroy your team. So why don't u include some cc ninja in your water team like ao or shurado. Pick the 3rd standard attack for water main because she can accupunture the enemy with that sa. In addition, if you need more cc, just switch to fire main and include ao, shurado. So with all those ninjas you can have 3 people doing cc in a round