iCat or Momotaro makes this level very easy.
One of the easiest cyclone stages, due to the abundance of anti-red cats.
Momotaro in both his normal and evolved forms makes this stage a joke, but if you don’t have him it’s still fine.
Use Bean Cats for more knockbacks or for doing the stage with no gacha units.
Using many anti-Red and anti-Floating cats can make this stage easier than you'd think. After the Shy boys and St. Pigge is spawned, a lot of money could be accumulated to level up your wallet/spam cats. With the assistance of anti-red/floating cats, Attack on R-Cyclone can quickly be turned into the easiest cyclone stage.
Strategy 1 (Classic strategy)
Wall Cat, Brah Cats (optional), Sorceress Cat, Necromancer Cat, Sword Master Cat, Drama Cats, Dragon Cat, True Valkyrie Cat (normal Valkyrie works too) and Bahamut Cat. Note: Most, if not, all cats should be at least level 20 and Rich Cat really helps at the beginning of the battle, but it is not required to beat the level.
All you have to do is to spam Sorceress Cat, watch the red cyclone get shredded, and enjoy.
However, do note that slowed enemies still move, so it would be best if something like Pirate Cat is brought along. Played right, this stage can be a breeze.
The One Horns fill up your wallet, making this the easiest Cyclone stage.
Another reason why this stage could be so easy is because of the humongous amount of anti-red + anti-floating cats.
Strategy 2 (ft. iCat)
It requires iCat, meatshields, and a heavy hitter(s) like Bahamut Cat. Just spam iCat and your meatshields until you can afford (all) your heavy hitter(s) Then buy your heavy hitters and stop meatshielding but keep the ICats. Bam. Completed.
Lineup: (all at least lvl 20) Mohawk, Wall, Samba, Ninja, Pirate (or other anti reds/floating with freeze/slow/kb ability), Paris, Dragon, Whale (or other anti-red/floating). Remaining slots can be filled with strong attackers (Bahamut Cat) or ubers if you have any.
This is mostly a combination of two different strategies, (1 and 4). Pirate is preferred but theoretically other anti reds/floating that are spamable with similar abilities would also do the job.
Start off by sending a few meat shields, this should be enable you to lvl up your worker cat to at least 3 before pigge comes out. Shortly afterwards the Shy boys will also be spawned, and you can begin to stack your ranged attackers (paris, dragon) and spam pirate in preparation for the cyclone. At this stage, your worker cat should be about maxed and your wallet full. As your cats near the enemy's base, begin to spam all your cats and meat shields. (Do not worry about money as the horns should be easily defeated, providing extra money). After the boss appears, it should barely be able to move due to your pirate stack. Even if it does the extra meat shields should provide enough time for your attackers to kill it. Good luck!