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After you complete the World Axle - Shaft, you will drop to the World Axle - Deepest Level. Once you land here, The elevator to town will become available, so if you have taken too much damage, go back to town and heal now. Cobalion will also join you, but once you go back to town he won't be here. To the North of the elevator is the only building in the area - the Dark Rust's Fort, where Dark Rust's Forces, and the Dark Rust itself will be fought.
Dark Rust's Fort
When you enter the Dark Rust's Fort, a cutscene will play. After then, you will be able to select teammates for the final battle. Cobalion will be standing near the catapult. All Pokémon encountered in the level will be rusted, which is mostly a visual effect.
Dark Rust's Fort
Recommended Power Level:2100+
- A Pokémon of the Ice-Type, Ground-type or Dragon-Type is strongly recommended, Mainly against Zekrom. If you don't you can be in big trouble. Garchomp, found in the cave, can be a good choice, but it is extremely rare.
- Watch out for Spinda in the first chamber. its Teeter Dance can make you confused.
- The second and third chambers are usually not a problem, as the seemingly-intimidating bosses are not that difficult. You should be able to take care of them quickly.
- The Zekrom in the fourth chamber is a tough opponent as it can kill all your Pokémon in a few hits unless they have a healing move such as Drain Punch. Use Hyper Mode to take care of it. You can use the Swaparound to Change into the recommended types above, although you should have one in the lead already.
- After the words "It's time to stop playing around!" appear, Dark Rust appears. It will be invincible at first as its barrier will dodge all your attacks and restores it to full health once its HP goes to half. DO NOT waste your windup energy for this, as it is futile to do so. Instead ignore it and defeat the Sigilyph and Unown for windup energy.
- After two activations of the barrier, Cobalion will sacrifice itself to break the barrier. After this you will be restored to full health, and Dark Rust can be beaten just like any other boss. Again, due to the number of enemy Pokémon you should have enough windup energy to pull Hyper mode to do a quick finish.
- Congratulations! Now watch the endgame cutscene and the credits! But wait, this means for a whole new adventure!