First, let's summarise the goal in mind. During the course of Chapters 15-19, your character will undergo special "Training Sessions" in Free Time to acquire his/her Bankai. If you meet certain requirements, you will have yourself a Bankai, making the final boss a walk in the park. If you do not meet these requirements, you will get Shunko, though pleasing as it is, it's nowhere near as good as Bankai. This is a very tricky process, and there have been many theories and guesses as to which method works out best to get Bankai early. But there is only one way that I have encountered which will get you Bankai early. During the five chapters leading up to the fated Bankai release, you will do some Free Time events. There you will see numerous icons of a character with a sword next to them and the name will always begin with "Training". The objective here is to do every single one of these training icons and win. Failing one will deny you Bankai and give you Shunko instead. Some are very easy, but some really demand hardcore strategy and careful planning. Here is the list I done that got me Bankai:
1) Zanjutsu Training 1 (The icon with Ichigo). This Session requires you to defeat Hollows with Fujimaru/Matsuri, Ichigo, Renji and Komamura. Simple? Wrong. Every turn they fully heal themselves. And you need to complete it in five turns or fail. The small Hollows, like Screamers are no problem, but against the bigger Hollows like Numb Jelly that pack 1500 HP, it can be tricky. The key here is to have Ichigo, Renji and Komamura go Bankai. I used an equip that raises their Spiritual Pressure to Max, getting Bankai within the second turn. Have Renji, Komamura and Tenken Myo-oh attack the Hollows to the north and Ichigo and your character deal with all others. Handy tip: If you have Sokatsui for your main, it's easier to take down large Hollows, because every square Sokatsui hits on the Hollow accumulates, doing 1000+ damage. It's advised that you save before doing this, that way if you mess up, you can go back and try again. If all goes to plan, then you'll complete the training session.
Zanjutsu Training 2 (The icon with Ikkaku). Here, you need to defeat Ikkaku, Yumichika and Yachiru alone. Do NOT attack Yumichika or Yachiru. If you kill Ikkaku, the other two will bow down in defeat. If your character has the Tech weapon choice, this is a breeze, if not, don't worry. But here's the kicker: after you defeated Ikkaku, Kenpachi joins the fray to do a one-on-one with your character. Just fight Kenpachi until he dies and that's it complete. Again, it's where the Tech weapon comes in handy, but don't panic if you got Power or Speed.
Kido Training 1 (The icon with Kukaku). This one gave me the biggest headache. You have to defeat eight Hollows with Fujimaru/Matsuri and Kukaku...using only Kido. And If Kukaku dies, it's a fail. I heard rumours you can counter to kill, but me being me, I decided to play it safe and do only Kido, you can test it if you so please. If you want to do Kido only, just guard instead of counter when the Hollows attack. Take two steps backwards with your main behind Kukaku. This will mean the two Hollows to North can't hit you. When it's your turn next, bombard the two with Sokatsui and Raikoho, and hopefully it'll kill them. Once the Hollows to the West and East start attacking, get Kukaku out of there immediately, she won't last long against them. Your main should handle him/herself, but it is advised you have at least one Kido that you can move with. Handy tip: Watch out at the Hollows to the East, they use a variation of Byakurai, which inflicts Shock on one of your characters, which will effectively make them useless; it is advised once they come to you after you defeat the northern Hollows that you defeat them next. If all plays out, you should win. But it's not over yet. Because Kukaku now challenges you to a fight. Do the same things against the Hollows and blast her with Shakkaho or Sokatsui and you'll win much easier.
Kido Training 2 (The icon with Byakuya). This one's a little easier, but does deserve caution. You need to defeat Byakuya and Rukia with your main and Yoruichi, twice. You can now attack, but for the sake of what the training is for, I used Kido all the way, but used Yoruichi to weaken the two using normal attacks. This one shouldn't pose too much of a threat, unlike last time.
Hakuda Training 1: (The icon of Soi Fon). You need to defeat Hollows with your character, Soi Fon and Chad. Have Chad go to the Hollows on the left and Soi Fon to the right. It should be easy for them with their affiliation advantages. After they're done, two more Hollows appear behind your character, which'll be easy to defeat. Simple.
Hakuda Training 2: (The second icon of Soi Fon). This one's a little trickier. You first need to defeat a powered Soi Fon with your character and Yoruichi. Shouldn't be too much trouble, the real problem is afterwards. Your team-mates switch, so you need to defeat Yoruichi with Soi Fon and your character. Her stats increase, so she'll be faster and stronger. Just keep pounding her until she dies. Handy tip: Never perform Flash Step attacks on either opponent. They're immune to it.
FSRA Training (The icon with Yachiru). A fun little battle where the Female Soul Reaper Association (Rukia, Yachiru, Soi Fon, Nemu, Momo and Rangiku) add Yoruichi and your character into a divided mock battle. All you need to do is pick heads or tails and pair up with certain characters and defeat the others. I chose Heads and got Rukia and Yoruichi, so just defeat all the others with your three characters and that's it, simple.
Elite Training (The icon with Hisagi). Here you need to defeat Hollows with your character, Hisagi, Momo, Kira and Renji. Have all of them defeat a Hollow in battle (No Kido or skills), they give an explanation and your character learns from them. Them you can go wild on them. Pretty easy, really.
Karakura Training (The icon of Ichigo). Here you need to defeat Hollows with your character, Ichigo, Chad, Uryu and Orihime. To pile on the pressure, you need to perform Konso on three Wholes or you fail, typical. Push your character North to where the Whole is, and have Ichigo push South, while using pressure , it's almost vital he's in Bankai by the time he performs Konso on the Whole to the South. Meanwhile, have everybody else fight the Hollows and make your two Soul Reapers job more easier. When Ichigo has Bankai on and performed Konso on the Whole to the South, race to the Whole on the West and perform Konso on it as well. And if you haven't defeated any Hollows yet, quickly do so.
World of the Living Training (The icon with Urahara). This one is very tricky, but easy when you figure it out. You need to defeat Kon and Don Kanonji, but their stats have gone way up. Don't recklessly attack them, they'll either dodge you, or defend and knock you out easily. What you need to do is run to the side with Kon. He'll give chase and attack you. Block the attack, do NOT counter, Kon's attack will be dulled. Kanonji won't be able to reach you so can't attack you. Keep running from Kon as he keeps attacking you, while the Don will try to keep up. And here's the trick: their stats will lower with every turn. When the two's stats are low enough, go on the counterattack and flatten them. Make sure to bring plenty of healing equipment.
With that, the training will be complete, and all you need to do now is play through the story until you get your Bankai.
*Don't worry about character recruitment icons, they'll carry on to the next Free Times later (Except the one in Doppelganger) *It goes without saying, but the training icons are not in order, so if you can't complete one, come back later when you think you're ready. *Additionally, you can't get them all in one chapter. I got mine in two. So when you get to the main story character preparation screen, use that to your advantage to either train in Free Battle or stock up on the necessary equipment you may need. *Also there will be times when nearly all of your training icons will lead to pitfalls. If that be the case, just select an icon unrelated to training that will lead away from the pitfalls. This same method is used when trying to get equip chests, stat boosts and Discounts. *The strategies I give aren't the word of God. If you can find an easier method to beat them, give it all you got.
With that, I wish you luck and hope you get Bankai.
There is only one thing you need to remember when making a team, and that is that any team is the best team as long as you have Hanataro and either Rukia or Captain Unohana on your team because with their healing ability your people will never die as long as they aren't at low levels
After you finish the game and unlock the the Bleach Tower reach level 21. When you get into the level Have Hitugaya on your teach. When you reach Kusaka have Hitsugaya talk to Kusaka. If Hitsugaya fights Kusaka at lest once that will unlock Kusaka.
The Larger Hollows are really hard to get rid of. They hold a lot of power and can deal a lot of Damage. But to deal damage by the thousands on these hollows are simple. The secret is in Skills. These Larger Hollows take up more space. For Example the Menos Grande takes up four spots. The thing to do is to use Sokatsui either right next to or close to them. The Sokatsui attacks for then one pannal at a time. Using that will help against the hollows.