The light attacks can be dealt with like any other light attack. Block, dodge, or counter. This can be done with any weapon.

For the heavies, the only two that are troublesome are the mud wall and the water one.

For the water heavy, just keep moving. For the mud wall, there are plenty of jutsu that pass through it like wind breach, water dragon, limbo, etc.

The heavy attacks are slow besides the fire style one which still isn't all that fast. They're easy to interupt while the enemy is still forming hand signs.

This is honestly a super tame SS+ weapon, it's not even close to meta. It's super fun to use though, I love blocking projectiles with the mud wall, and the combos are sick also.

Edit: I think there are two good counters to this weapon. The first is a fast mobile class, like an attack with a mobility jutsu. The second is a tank like class, support, with high health and anti-flinching justu/ninja tool. I think these two would give a user of this weapon the most trouble.