1-24 (Discord) - The Shinigami struggles to maintain or fully manifest their Sword Spirit, though as they progress it gradually becomes easier to do so.
25 (Harmony) - The Shinigami gains enough proficiency that they can consistently manifest and maintain their Sword Spirit, allowing them to challenge them so as to attain Bankai.
26-49 (The Trial) - The Shinigami partakes in their Sword Spirits Challenge(s) in the interest of coming into a state of greater union with them. This can take virtually any form. Notably, the Sword Spirit will demonstrate the capacity to manifest some or all of their Shinigami’s shared inner world to facilitate these trials.
50 (Union/Resonance) - The Shinigami has Dominated their Sword Spirit and/or passed the necessary trials and challenges necessary to learn part or all of their Spirit’s True Name. Those with full mastery of their Shikai gain the entire True Name of their Sword Spirit, whereas those who don’t merely gain a fragment of it–the former is referred to as Union, whereas the latter is Resonance. This affects the manifestation of their Bankai. Notably, the endpoint for these two paths may look different, but no path is truly inferior to the other. At this stage, the shinigami thus gains access to their Bankai’s base ability. Shikai techniques may be used in Bankai. Additionally, all Bankai passively grant the Shinigami higher effective Reiatsu than their baseline stats would. Those of the Union Path gain an additional Stat Enhancement beyond their Reiatsu, whereas those of the Resonant Path do not–notably, this Stat Enhancement may be different from that of Shikai, and it does not stack, nor does the Shikai Stat Enhancement carry over into Bankai.
60 (1st Stage) - At this stage, those of the Union Path gain access to
enhanced versions of their first three Shikai Techniques. Those of the Resonant Path gain access to their first
Bankai Technique*.
70 (2nd Stage) - At this stage, those of the Union Path gain access to
enhanced versions of their second set of three Shikai Techniques. Those of the Resonant Path gain access to their second
Bankai Technique*.
80 (3rd Stage) - At this stage, those of the Union Path gain access to
enhanced versions of their third set of three Shikai Techniques. Those of the Resonant Path gain access to their third
Bankai Technique*.
90 (4th Stage) - At this stage, those who follow the Path of Resonance gain their fourth Bankai technique. However, unlike those that come before, these–and all that follow–are Advanced Bankai Techniques. These are meant to be trump cards, they are the finale, the last resort, and certainly the cream of the crop. Yet, those shinigami who follow the Path of Union now begin to see the true fruits of their labor, for it is at this stage that their Bankai truly blossoms, affording them a single Transformative Technique. Abilities of this sort take on an entirely different form. Unlike Advanced Techniques, these tend to take on entirely different forms. Whereas an Advanced Technique might serve as a distinct individual advantage, Transformative Techniques change the game itself, turning it entirely on its face.
100 (Cocoon) - The final traditionally accepted stage of Bankai, the Cacoon Stage differs–as one might expect–depending on the Path one has followed up until this point. For those who walked the Path of Resonance a Stat Enhancement is gained, this Enhancement follows the same rules as that gained by the Union denomination earlier on their Path. In addition to this, the Cacoon Stage affords the Resonant with a single Transformative Technique. On the other end of the spectrum is the Path of Union, who gain an additional Stat Enhancement and a boost in the potency, nuance, or versatility of their Bankai’s base ability.