It is slower than the original Mooth, but has more health and more range. It deals 8,000 damage per attack and is able to weaken Cat Units. It loses the 1-knockback characteristic most of Mooth's variants have.
Using Kotatsu Cat is a very viable strategy to stall and weaken Sister Lione. Also, Lizard Cat and Crazed Lizard Cat both outrange Sister Lione by 25, thus they should be able to quickly deal with her when paired with Kotatsu Cat. She normally acts as support, hiding behind the front lines, therefore Long Distance Cats can snipe her while other units deal with the front.