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Bane starts off invincible to any attack. Avoid him until he rams you. Dodge him to put him off balance, then strike. Afterwards, you must make him ram into a wall. After beating him up, he will stomp to make strange boulders fall from the ceiling. After those attacks are dodged, repeat. After you knock out his health, he returns stronger. Repeat the previous steps to defeat him.
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Clayface can shoot muck which spawns little muck monsters, turn his arms into sledgehammers/razor blades, or ram you with a brick wall if you get too close. The trick is in the two electric outposts-like things on either side. Dodge until they turn green. Then, quickly hit each with a Batarang or your fists. This will turn on the electricity. He will be stunned. Hit Clayface's face and repeat this until he is defeated.
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Scarecrow is fairly easy, because he rarely attacks. To start off, look down at the floor. It is covered with some sort of blue gas. The trick to defeating him is as follows. First, avoid or destroy all of the ghosts flying around. Notice how the gas seems to part in certain areas (but not your own). This is Scarecrow walking. Roll into him. He is invisible, and this lets you see and beat him up. After awhile, he turns invisible again. Repeat the steps until he is defeated.
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Sin Tzu is blindingly fast, amazingly strong, and invincible to any non-Power Attack. Start by letting him run at you. He will do a four-hit dash. Dodge all times and he will do a backflip. Hit him. Repeat this until your Power Meter is full. Then when he backflips, hit him hard. After a few attacks, he will jump into his tower. He will summon units, regain health, and shoot fire at you. After you defeat the enemies, he will stop healing and fight you. This part is all the same, except he will occasionally move to the room's center and do a crazy attack. The only hope to dodge this is to block.
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