The boss, Metal Cyclone, will appear when the enemy base's HP is down to 90%.
Only 2 enemies may be on stage at once, one's deployment may be delayed until after another enemy is defeated.
During the boss fight, these enemies will appear in the following pattern: Metal Hippoe -> Super Metal Hippoe -> Metal One Horn -> Sir Metal Seal -> Super Metal Hippoe After that, every ~70 seconds, 1 Super Metal Hippoe will be spawned.
The cyclone stages previous to this are key to beating this stage: they give you anti-metal cats that are vital to success here.
The use of Critical Hitters is mandatory in this stage (yes, you can also spend hours and go without).
The three units which break the stage are Tesalan Pasalan, Kyosaka Nanaho and Beserker Cat. Tesalan can one-shot the Metal Cyclone starting from level 12 (providing that it crits), Kyosaka will take an average of only 25 seconds to kill the Metal Cyclone and Beserker will take an average of 29 seconds.
Lineup: 3 meatshields and as many anti-metals and critters as you can.
Start by building up your worker, then summon something and try to deal with Metal Hippoe while building up your anti metals (Kaguya, Poseidon, other cyclone drops...). Once he gets a knockback, spam the crit hitters too. The key to this strat is getting a good enough stack to stall the peons and deal damage regularly since it's rng based; you may need to try a few times if your units are weak or you may have to add sniper.
Strategy 2 (Cheese)
The goal is to exploit the "max number of enemies"
Lineup: one or two meatshields (Crazed Tank/Tank), high damage or high DPS (fast attack rate optional) Cats (Bahamut, Crazed UFO, Paris etc.) and Metal knockback cats (Bronze/Michelangelo). Shinji Cat (Evangelion Collab) is extremely useful if you have it.
After ~1 min 39 seconds, the first Hippoe will spawn. Start "spamming" Michelangelo Cats between 1 min 30-35 seconds into the battle, and summon maybe one or two tanks to keep them alive.
After ~2 min 10 seconds into the game, Super Metal Hippoe will spawn. Start spamming all your damage cats about 2 min into the game (Tank Cats too). Hopefully, by this time, both Hippoes will have been knocked back to behind the base. Now they'll be "invincible" and the enemy base will be free for you to attack without having to worry about the Metal Cyclone.
- Note that Riceball Cat will help here as it will stop the Super Metal Hippoe from pushing back the meatshields.
- Note that Super Metal Hippoe outranges Bronze/Michelangelo cat, so you have to keep them protected with units with high health such as Jamiera and Crazed M. Titan. LD units that can snipe the base can also come in handy (I used Nobilan Pasalan, but likely Megaphrodite can also work).
- This stage appeared for the first time on March 24th, 2015.
- This stage will appear every Sunday thereafter.
- This stage appears every Sunday.
- December 28th, 2014 to January 1st, 2015 (first time)
- Attack on Titanium is one of the only stages in the game to consist entirely of Metal enemies, the others being Bionic Seaweed, Nuts 'n' Bolts, Floor 14, and Clash of Steel (Merciless).
- The english stage name is a reference to Japanese manga series: Attack on Titan.