The Wormhole Opens is the 9th Cyclone Stage/the 5th limited Deadly stage. It introduces the Super Cosmic Cyclone, which is a non-Floating Cyclone like Zyclone, Divine Cyclone, Primeval Cyclone, and Metal Cyclone. Upon completion, players have a 30% chance to unlock Volley Cat. It appears every Sunday.
This stage cannot be played until Cats of the Cosmos Chapter 1 has been cleared.
Battleground
Super Cosmic Cyclone, a Starred Alien Cyclone spawns at the beginning of the level. About ten seconds later, the first peons begin to spawn, Shibalien Elite and Mistress Celeboodles. This pattern repeats as the battle progresses: Mistress Celeboodles every 4 seconds, Shibalien Elites every 20 seconds, Star Pengs every 26-36 seconds, and General GreGories every 13 seconds.
Strategy
An ideal strategy to find your way past this stage is to try to slow the Super Cosmic Cyclone as much as possible. Slow down the Cyclone with slow or freeze effects. Weakening it can be worthwhile too because of the damage it inflicts being moderately low to begin with. In fact, if one uses Thaumaturge Cat, a level 40 Crazed Tank cat can endure 1 blow without being defeated. Also use stallers (use a tanky Uber like Mission Control Mekako if you need to) so you can inflict the effects.
Corrupted Psychocat is quite helpful in this stage. It can be used to easily stall the boss. Macho Leg Cat also works well due to its anti-Alien ability. On the Uber Rare side of the spectrum, Cat Machine Mk 3 is noteworthy due to its impeccable defense and Alien Resistance. However, it is not particularly good as it will be warped constantly. Megaphrodite is an incredibly potent long-ranged attacker, as is Catman. Because Super Cosmic Cyclone only has a range of 275, Thaumaturge can be used to slice its attack power in two. Oni Hayabusa gets a special mention as it can knockback and slow SCC, as well as the fact that when SCC has been hit by Thaumaturge, Oni Hayabusa can tank around 10 blows.
Warp Blocker cats will fare very well here as they will not be interrupted. However, if they are attacked they will quickly die as they will not be Warped to a safer distance. One good example is Rover Cat, only if it is hypermaxed. DO NOT USE SEAFARER CAT AS HE IS OUTRANGED.
Maxing out the anti-Starred Alien Treasures from Cats of the Cosmos Chapter 1 is highly recommended, or else the Super Cosmic Cyclone and its supports might be too powerful to deal with.
Strategy 1
All you need is Catellite and Freshman Cat Jobs. At the start of the battle, send 1 Catellite to stall SCC a bit. Lure the enemies to your base and then slaughter them. After that, let SCC hit your base, then spawn Freshman. SCC damage will be reduced to nothing and then shoot your cat cannon so SCC isn't hitting your base anymore. Let your debuffers and damage dealers (I used Akira and Immortal Shingen) to destroy SCC. Make sure to kill it before the Gregory arrive.
Walkthroughs
| Walkthrough Video | Player | Notes |
|---|---|---|
 The Battle Cats - The Wormhole Opens (deadly) The 2nd Dimension No Uber | Danie A | No uber are use in this video |
| https://www.youtube.com/watch?v=CTWMQU6JxAg | SilumanTomcat | A level 40+23 Li'l Macho Legs Cat is used in this video. |
| https://www.youtube.com/watch?v=YXczgG0a9sw | Dcyx | This video uses two Metal Slug Defense units. |
Trivia
- In BCEN, this stage's first occurrence should have taken place on Thanksgiving Day.
- This is the first and only Deadly Cyclone Stage (not including the Deadly Carnival events).
- The background in The Wormhole Opens is the same one that appears in Black Hole.
- This stage used to count a limited Deadly stage like Realm of Carnage, since it lasts for 3 days and is a No Continues stage. In version 6.8, however, PONOS changed its schedule to every Sunday so it now shares the same schedule with Attack on Titanium.
