This guide will give you a few guidelines and tips to go through the Climax Battles in Yakuza Kiwami.
Proving Ground 1: Switch to Rush immediately and go behind you. You will meet a rifle guy that you need to take down fast. If you feel lucky, switch to Brawler and grab the rifle. Shoot the bad guys but but be careful. Once this is done, you should have enough heat. Switch to Dragon and Sumo Slap the Chainsaw guy. The rest should be easy.
Proving Ground 2: Not so hard. Don't forget to use Beast to grab heavy objects to clear the trash fast.
Proving Ground 3: Immediately deal with the two gun guys that will annoy you quite fast. Be careful of the sword guy too. Other than that, go Beast and grab objects to clear the level.
Proving Ground 4: Easy. Use Brawler to build heat then grab a guy and use heat action on him. Do that to everyone.
Proving Ground 5: Stupid level. You need to get hit and use counter attacks to deal damage. This is mostly a luck base level. His high kicks tend to be the easier attacks to counter.
Proving Ground 6: You can only use rush with Sturdy Brass Knuckles. You can't get hit and must stay in heat mode. It seems hard but it's not. Rush the nearest gun guy and beat him. Be careful to check behind you when you start, there are enemies there too. At the end you will face a sword guy and two gun guys. Fall back so you can't get shot and lead the sword guy to you. Wait for him to attack and use the Sword Counter Heat Action. If you're full, it should kill him and you should have enough heat remaining. After that, kill the last two gun guys.
Proving Ground 7: This is a hard mission. You're locked in Beast, you have the golden gun and need to clear the level. You can't get hit. The trick is to press R1 & Triangle at the same time to shoot. And then do it again. This way you will fire like a machine gun. Sometimes enemies are hidden behind walls. I suggest to run this level a few times to check enemy placement and then attempt to do it. The last enemy will dodge bullets a few times.
Proving Ground 8: Hope you're good a Tiger Drop. Cause you will need it to clear the level fast. Other than that, no really good advice. You need to clear the level as fast as possible so don't hold back and use heat actions as much as you can.
Proving Ground 9: It seems hard but it's not. You have zero life and need to protect the girl from zombies. Build heat in Brawler, switch to Dragon and use sumo slap. Using heat actions in Dragon will restore your life. Keep doing this and you will clear this easily.
Proving Ground 10: You control Drunk Date. Deal with the gun guy first and then kill the other ones. Date can't take much damage so be careful. Whatever you do, kill the ones with weapons first.
Melee Battle 1: Not too hard. You need to kill everyone. Don't forget to use objects and beast to deal with enemies and you should not have too much trouble.
Melee Battle 2: Piece of Cake. Build heat and then use it on the boss. Rince and repeat. Combo the boss into submission once he's alone.
Melee Battle 3: It's a TRAP. No really, you need first to hang around to arena so ALL the enemies come to you. Build some heat and go beast on them.
Melee Battle 4: Deal will the stungun guys first. The rest should be easy enough. Use tables and objects if you meet some troubles.
Melee Battle 5: Easy, again. You need to clear the room. But you're stuck in Brawler. Use tables and objects to clear the room easily.
Melee Battle 6: Deal with the Shimano Family using only Rush. Do a full rush combo and end it with a charge kick. Easy.
Melee Battle 7: Not too hard. You're stuck in beast. First deal with a gun guy, pick his gun and shoot everyone. Keep doing that. Once the boss come out, try to deal with the small fry first then deal with the boss.
Melee Battle 8: Very HARD and Very LONG. Basically this is the entire level with the Arase fight. Except you're stuck with a very weak Dragon. But you have a few abilities. Notably you have most of your heat actions. Only building heat is a pain. Don't be afraid to go into room to pick a few healing items. And don't forget to grab enemy guns when you can, it will make the level a bit easier. Once you get to Arase, keep the Target button pressed to easily dodge his attacks and combo him from behind. Don't use more than 3 hits or he'll dodge and counter attack. This is a battle of patience, don't losr your cool.
Melee Battle 9: Ignore the enemies and get to Majima as fast as possible and beat him. Your only problem with be Majima. He's not too hard and you're full powered with all the styles.
Melee Battle 10: Yakuza 0 flashbacks. You fight some grunts, Kashiwagi and Sera. Kashiwagi isn't too hard, build some heat and crush some chair on his head. Proceed to the end but keep your heat full. Once you get to the end, ignore the fodders, grab an object and crush Sera with an heat action. Use the fodders to build heat and repeat. After that, Sera shouldn't have much health left.
Mad Dog Battle
Mad Dog Battle 1: Easy. You need to fight Majima in rush. Just don't be too close to him and try to combo him from behind.
Mad Dog Battle 2: There's a trick. There are 3 officers but only one Majima. You can't damage the real officers. So target Majima and grab him over and over.
Mad Dog Battle 3: Zombie Majima isn't quite hard. Just don't rush blindly. Use Kiryu's L1 + Triangle if he's too agressive ot give yourself some space.
Mad Dog Battle 4: Not too hard either. Build some heat in brawler and then pick up objects to crush Hannya-Man. Or grab him and use heat actions. Don't be too long other the others Hannya-Man will appear. Beat the three of them to clear the level.
Mad Dog Battle 5: Just tiger trop everyone and call it a day.
Just a fancy name for Boss Rush I guess. Probably the most enjoyable part for me. You have a full upgraded Kiryu with all the styles and need to take down all the bosses. It's unlocked once you clear every other Climax Battle.