Attack on R-Cyclone is the first level in Cyclone Stages. It appears every monday.
Some B.B.Bunnies will begin to spawn at the start of the level and St. Pigge the 2nd will spawn shortly after you begin. Shy Boys will then begin to spawn (about 5 of them). After you attack the base, Red Cyclone will spawn, with 3 One Horns. The One Horns will constantly respawn throughout the battle after the red cyclone is spawned.
Using many anti-red and anti-floating cats can make this stage easier than you think.
Wall Cat, Brah Cats, Sorceress Cat, Necromancer Cat, Sword Master Cat, Drama Cats, Dragon Cat, True Valkyrie Cat and Bahamut Cat (most, if not, all cats should be at least level 20 and rich cat really helps in the beginning of the battle, but it is not required to beat the level)
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.
It is recommended to bring along Rich Cat and Sniper the Cat.
Please note that this strategy is only effective if you have all Superior Treasures from Empire of Cats Chapters 1 & 2. Chapter 3 Treasures also help.
Start by spamming Wall Cat. You will be doing this throughout the battle.
Once the B.B.Bunnys start coming out, spam Wall Cat and Ninja Frog Cat. To efficiently do this, while also gaining money, use a pattern like this: Wall/Ninja Frog/Wall/Repeat. This will allow you to build up money, albeit slower than just Wall Cats.
Once you've gained enough money, spawn Thundia.
When the Shy Boys spawn, spam everything you have (except Angry Delinquent, Whale, Thundia) to slow them down long enough to allow Thundia to defeat them.
Once the Cyclone comes out, spam everything. Do not turn off Sniper the Cat at any point. If you send out enough Pirate Cats and other knockback or freezing units, the Cyclone should barely be able to move for a good time.
Once the Cyclone is down, destroy the base and you win!
The One Horns will, as stated above, provide extra money, allowing you to continue spamming.